diff --git a/plugins/YammerImport/README b/plugins/YammerImport/README
new file mode 100644
index 0000000000..975faa2132
--- /dev/null
+++ b/plugins/YammerImport/README
@@ -0,0 +1,182 @@
+Yammer Import Plugin
+====================
+
+This plugin allows a one-time import pulling user accounts, groups, and
+public messages from an existing Yammer instance, using Yammer's public API.
+
+Requirements
+------------
+
+* An account on the Yammer network you wish to import from
+* An administrator account on the target StatusNet instance, or
+  command-line administrative access
+* This YammerImport plugin enabled on your StatusNet instance
+
+
+Limitations
+-----------
+
+Yammer API key registrations only work for your own network unless you make
+arrangements for a 'trusted app' key, so for now users will need to register
+the app themselves. There is a helper in the admin panel for this.
+
+In theory any number of users, groups, and messages should be supported, but
+it hasn't been fully tested on non-trivial-sized sites.
+
+No provision has yet been made for dealing with conflicting usernames or
+group names, or names which are not considered valid by StatusNet. Errors
+are possible.
+
+Running via the web admin interface requires having queueing enabled, and is
+fairly likely to have problems with the application key registration step in
+a small installation at this time.
+
+
+Web setup
+---------
+
+The import process is runnable through an administration panel on your
+StatusNet site. The user interface is still a bit flaky, however, and if
+errors occur during import the process may stop with no way to restart it
+visible.
+
+The admin interface will probably kinda blow up if JS/AJAX isn't working.
+
+You'll be prompted to register the application and authenticate into Yammer,
+after which a progress screen will display.
+
+Two big warnings:
+* The progress display does not currently auto-refresh.
+* If anything fails once actual import has begun, it'll just keep showing
+  the current state. You won't see an error message, and there's no way
+  to reset or restart from the web UI yet.
+
+You can continue or reset the import state using the command-line script.
+
+
+CLI setup
+---------
+
+You'll need to register an application consumer key to allow the importer
+to connect to your Yammer network; this requires logging into Yammer:
+
+  https://www.yammer.com/client_applications/new
+
+Check all the 'read' options; no 'write' options are required, but Yammer
+seems to end up setting them anyway.
+
+You can set the resulting keys directly in config.php:
+
+    $config['yammer']['consumer_key'] = '#####';
+    $config['yammer']['consumer_secret'] = '##########';
+
+Initiate authentication by starting up the importer script:
+
+    php plugins/YammerImport/scripts/yammer-import.php
+
+Since you haven't yet authenticated, this will request an auth token and
+give you a URL to open in your web browser. Once logged in and authorized
+there, you'll be given a confirmation code. Pass this back:
+
+    php plugins/YammerImport/scripts/yammer-import.php --verify=####
+
+If all is well, the import process will begin and run through the end.
+
+In case of error or manual abort, you should be able to continue the
+import from where you left off by running the script again:
+
+    php plugins/YammerImport/scripts/yammer-import.php
+
+To reset the Yammer import state -- without removing any of the items
+that have already been imported -- you can pass the --reset option:
+
+    php plugins/YammerImport/scripts/yammer-import.php --reset
+
+This'll let you start over from the requesting-authentication stage.
+Any users, groups, or notices that have already been imported will be
+retained.
+
+
+Subscriptions and group memberships
+-----------------------------------
+
+Yammer's API does not expose user/tag subscriptions or group memberships
+except for the authenticating user. As a result, users will need to re-join
+groups and re-follow their fellow users after the import.
+
+(This limitation may be lifted in future for sites on the Silver or Gold
+plans where the import is done by a verified admin, as it should be possible
+to fetch the information for each user via the admin account.)
+
+
+Authentication
+--------------
+
+Account passwords cannot be retrieved, but the primary e-mail address is
+retained so users can reset their passwords by mail if you're not using a
+custom authentication system like LDAP.
+
+
+Private messages and groups
+---------------------------
+
+At this time, only public messages are imported; private direct and group
+messages are ignored. (This may change with Silver and Gold plans in future.)
+
+Yammer groups may be either public or private. Groups in StatusNet currently
+have no privacy option, so any private groups will become public groups in the
+imported site.
+
+
+Attachments
+-----------
+
+Attached image and document files will be copied in as if they had been
+uploaded to the StatusNet site. Currently images do not display inline like
+they do on Yammer; they will be linked instead.
+
+File type and size limitations on attachments will be applied, so beware some
+attachments may not make it through.
+
+
+
+
+Code structure
+==============
+
+Standalone classes
+------------------
+
+YammerRunner: encapsulates the iterative process of retrieving the various users,
+              groups, and messages via SN_YammerClient and saving them locally
+              via YammerImporter.
+
+SN_YammerClient: encapsulates HTTP+OAuth interface to Yammer API, returns data
+                 as straight decoded JSON object trees.
+
+YammerImporter: encapsulates logic to pull information from the returned API data
+                and convert them to native StatusNet users, groups, and messages.
+
+Web UI actions
+-------------
+
+YammeradminpanelAction: web panel for site administrator to initiate and monitor
+                        the import process.
+
+Command-line scripts
+--------------------
+
+yammer-import.php: CLI script to start a Yammer import run in one go.
+
+Database objects
+----------------
+
+Yammer_state: data object storing YammerRunner's state between iterations.
+
+Yammer_notice_stub: data object for temporary storage of fetched Yammer messages
+                    between fetching them (reverse chron order) and saving them
+                    to local messages (forward chron order).
+Yammer_user,
+Yammer_group,
+Yammer_notice: data objects mapping original Yammer item IDs to their local copies.
+
diff --git a/plugins/YammerImport/YammerImportPlugin.php b/plugins/YammerImport/YammerImportPlugin.php
new file mode 100644
index 0000000000..98c6ecd0ab
--- /dev/null
+++ b/plugins/YammerImport/YammerImportPlugin.php
@@ -0,0 +1,145 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @package YammerImportPlugin
+ * @maintainer Brion Vibber <brion@status.net>
+ */
+
+if (!defined('STATUSNET')) { exit(1); }
+
+class YammerImportPlugin extends Plugin
+{
+    /**
+     * Hook for RouterInitialized event.
+     *
+     * @param Net_URL_Mapper $m path-to-action mapper
+     * @return boolean hook return
+     */
+    function onRouterInitialized($m)
+    {
+        $m->connect('admin/yammer',
+                    array('action' => 'yammeradminpanel'));
+        $m->connect('admin/yammer/auth',
+                    array('action' => 'yammerauth'));
+        return true;
+    }
+
+    /**
+     * Set up queue handlers for import processing
+     * @param QueueManager $qm
+     * @return boolean hook return
+     */
+    function onEndInitializeQueueManager(QueueManager $qm)
+    {
+        $qm->connect('yammer', 'YammerQueueHandler');
+
+        return true;
+    }
+
+    /**
+     * Set up all our tables...
+     */
+    function onCheckSchema()
+    {
+        $schema = Schema::get();
+
+        $tables = array('Yammer_state',
+                        'Yammer_user',
+                        'Yammer_group',
+                        'Yammer_notice',
+                        'Yammer_notice_stub');
+        foreach ($tables as $table) {
+            $schema->ensureTable(strtolower($table), $table::schemaDef());
+        }
+
+        return true;
+    }
+
+    /**
+     * If the plugin's installed, this should be accessible to admins.
+     */
+    function onAdminPanelCheck($name, &$isOK)
+    {
+        if ($name == 'yammer') {
+            $isOK = true;
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Add the Yammer admin panel to the list...
+     */
+    function onEndAdminPanelNav($nav)
+    {
+        if (AdminPanelAction::canAdmin('yammer')) {
+            $action_name = $nav->action->trimmed('action');
+
+            $nav->out->menuItem(common_local_url('yammeradminpanel'),
+                                _m('Yammer'),
+                                _m('Yammer import'),
+                                $action_name == 'yammeradminpanel',
+                                'nav_yammer_admin_panel');
+        }
+
+        return true;
+    }
+
+    /**
+     * Automatically load the actions and libraries used by the plugin
+     *
+     * @param Class $cls the class
+     *
+     * @return boolean hook return
+     *
+     */
+    function onAutoload($cls)
+    {
+        $base = dirname(__FILE__);
+        $lower = strtolower($cls);
+        switch ($lower) {
+        case 'sn_yammerclient':
+        case 'yammerimporter':
+        case 'yammerrunner':
+        case 'yammerapikeyform':
+        case 'yammerauthinitform':
+        case 'yammerauthverifyform':
+        case 'yammerprogressform':
+        case 'yammerqueuehandler':
+            require_once "$base/lib/$lower.php";
+            return false;
+        case 'yammeradminpanelaction':
+            $crop = substr($lower, 0, strlen($lower) - strlen('action'));
+            require_once "$base/actions/$crop.php";
+            return false;
+        case 'yammer_state':
+        case 'yammer_notice_stub':
+        case 'yammer_common':
+        case 'yammer_user':
+        case 'yammer_group':
+        case 'yammer_notice':
+            require_once "$base/classes/$cls.php";
+            return false;
+        default:
+            return true;
+        }
+    }
+}
diff --git a/plugins/YammerImport/actions/yammeradminpanel.php b/plugins/YammerImport/actions/yammeradminpanel.php
new file mode 100644
index 0000000000..13960d9051
--- /dev/null
+++ b/plugins/YammerImport/actions/yammeradminpanel.php
@@ -0,0 +1,174 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Yammer import administration panel
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Settings
+ * @package   StatusNet
+ * @author    Zach Copley <zach@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class YammeradminpanelAction extends AdminPanelAction
+{
+    private $runner;
+
+    /**
+     * Returns the page title
+     *
+     * @return string page title
+     */
+    function title()
+    {
+        return _m('Yammer Import');
+    }
+
+    /**
+     * Instructions for using this form.
+     *
+     * @return string instructions
+     */
+    function getInstructions()
+    {
+        return _m('This Yammer import tool is still undergoing testing, ' .
+                  'and is incomplete in some areas. ' .
+                'Currently user subscriptions and group memberships are not ' .
+                'transferred; in the future this may be supported for ' .
+                'imports done by verified administrators on the Yammer side.');
+    }
+
+    function prepare($args)
+    {
+        $ok = parent::prepare($args);
+
+        $this->subaction = $this->trimmed('subaction');
+        $this->runner = YammerRunner::init();
+
+        return $ok;
+    }
+
+    function handle($args)
+    {
+        // @fixme move this to saveSettings and friends?
+        if ($_SERVER['REQUEST_METHOD'] == 'POST') {
+            $this->checkSessionToken();
+            if ($this->subaction == 'change-apikey') {
+                $form = new YammerApiKeyForm($this);
+            } else if ($this->subaction == 'apikey') {
+                if ($this->saveKeys()) {
+                    $form = new YammerAuthInitForm($this, $this->runner);
+                } else {
+                    $form = new YammerApiKeyForm($this);
+                }
+            } else if ($this->subaction == 'authinit') {
+                // hack
+                if ($this->arg('change-apikey')) {
+                    $form = new YammerApiKeyForm($this);
+                } else {
+                    $url = $this->runner->requestAuth();
+                    $form = new YammerAuthVerifyForm($this, $this->runner);
+                }
+            } else if ($this->subaction == 'authverify') {
+                $this->runner->saveAuthToken($this->trimmed('verify_token'));
+
+                // Haho! Now we can make THE FUN HAPPEN
+                $this->runner->startBackgroundImport();
+
+                $form = new YammerProgressForm($this, $this->runner);
+            } else {
+                throw new ClientException('Invalid POST');
+            }
+            return $this->showAjaxForm($form);
+        }
+        return parent::handle($args);
+    }
+
+    function saveKeys()
+    {
+        $key = $this->trimmed('consumer_key');
+        $secret = $this->trimmed('consumer_secret');
+        Config::save('yammer', 'consumer_key', $key);
+        Config::save('yammer', 'consumer_secret', $secret);
+
+        return !empty($key) && !empty($secret);
+    }
+
+    function showAjaxForm($form)
+    {
+        $this->startHTML('text/xml;charset=utf-8');
+        $this->elementStart('head');
+        $this->element('title', null, _m('Yammer import'));
+        $this->elementEnd('head');
+        $this->elementStart('body');
+        $form->show();
+        $this->elementEnd('body');
+        $this->elementEnd('html');
+    }
+
+    /**
+     * Fetch the appropriate form for our current state.
+     * @return Form
+     */
+    function statusForm()
+    {
+        if (!(common_config('yammer', 'consumer_key'))
+            || !(common_config('yammer', 'consumer_secret'))) {
+            return new YammerApiKeyForm($this);
+        }
+        switch($this->runner->state())
+        {
+            case 'init':
+                return new YammerAuthInitForm($this, $this->runner);
+            case 'requesting-auth':
+                return new YammerAuthVerifyForm($this, $this->runner);
+            default:
+                return new YammerProgressForm($this, $this->runner);
+        }
+    }
+
+    /**
+     * Show the Yammer admin panel form
+     *
+     * @return void
+     */
+    function showForm()
+    {
+        $this->elementStart('fieldset');
+        $this->statusForm()->show();
+        $this->elementEnd('fieldset');
+    }
+
+    function showStylesheets()
+    {
+        parent::showStylesheets();
+        $this->cssLink('plugins/YammerImport/css/admin.css', null, 'screen, projection, tv');
+    }
+
+    function showScripts()
+    {
+        parent::showScripts();
+        $this->script('plugins/YammerImport/js/yammer-admin.js');
+    }
+}
diff --git a/plugins/YammerImport/actions/yammerauth.php b/plugins/YammerImport/actions/yammerauth.php
new file mode 100644
index 0000000000..d0d4b40c71
--- /dev/null
+++ b/plugins/YammerImport/actions/yammerauth.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Yammer import administration panel
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Settings
+ * @package   StatusNet
+ * @author    Zach Copley <zach@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class YammerauthAction extends AdminPanelAction
+{
+
+    /**
+     * Show the Yammer admin panel form
+     *
+     * @return void
+     */
+    function prepare($args)
+    {
+        parent::prepare($args);
+        
+        $this->verify_token = $this->trim('verify_token');
+    }
+
+    /**
+     * Handle request
+     *
+     * Does the subscription and returns results.
+     *
+     * @param Array $args unused.
+     *
+     * @return void
+     */
+
+    function handle($args)
+    {
+        if ($this->verify_token) {
+            $runner->saveAuthToken($this->verify_token);
+            $form = new YammerAuthProgressForm();
+        } else {
+            $url = $runner->requestAuth();
+            $form = new YammerAuthVerifyForm($this, $url);
+        }
+
+        $this->startHTML('text/xml;charset=utf-8');
+        $this->elementStart('head');
+        $this->element('title', null, _m('Connect to Yammer'));
+        $this->elementEnd('head');
+        $this->elementStart('body');
+        $form->show();
+        $this->elementEnd('body');
+        $this->elementEnd('html');
+    }
+}
+
diff --git a/plugins/YammerImport/classes/Yammer_common.php b/plugins/YammerImport/classes/Yammer_common.php
new file mode 100644
index 0000000000..6ec6fc9041
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_common.php
@@ -0,0 +1,165 @@
+<?php
+/**
+ * Data class for remembering Yammer import mappings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Common base class for the Yammer import mappings for users, groups, and notices.
+ *
+ * Child classes must override these static methods, since we need to run
+ * on PHP 5.2.x which has no late static binding:
+ * - staticGet (as our other classes)
+ * - schemaDef (call self::doSchemaDef)
+ * - record (call self::doRecord)
+ */
+
+class Yammer_common extends Memcached_DataObject
+{
+    public $__table = 'yammer_XXXX'; // table name
+    public $__field = 'XXXX_id';     // field name to save into
+    public $id;                      // int  primary_key not_null
+    public $user_id;                 // int(4)
+    public $created;                 // datetime
+
+    /**
+     * @fixme add a 'references' thing for the foreign key when we support that
+     */
+    protected static function doSchemaDef($field)
+    {
+        return array(new ColumnDef('id', 'bigint', null,
+                                   false, 'PRI'),
+                     new ColumnDef($field, 'integer', null,
+                                   false, 'UNI'),
+                     new ColumnDef('created', 'datetime', null,
+                                   false));
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * DB_DataObject needs to know something about the table to manipulate
+     * instances. This method provides all the DB_DataObject needs to know.
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('id'           => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     $this->__field => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     'created'      => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has, since it
+     * won't appear in StatusNet's own keys list. In most cases, this will
+     * simply reference your keyTypes() function.
+     *
+     * @return array list of key field names
+     */
+
+    function keys()
+    {
+        return array_keys($this->keyTypes());
+    }
+
+    /**
+     * return key definitions for Memcached_DataObject
+     *
+     * Our caching system uses the same key definitions, but uses a different
+     * method to get them. This key information is used to store and clear
+     * cached data, so be sure to list any key that will be used for static
+     * lookups.
+     *
+     * @return array associative array of key definitions, field name to type:
+     *         'K' for primary key: for compound keys, add an entry for each component;
+     *         'U' for unique keys: compound keys are not well supported here.
+     */
+
+    function keyTypes()
+    {
+        return array('id' => 'K', $this->__field => 'U');
+    }
+
+    /**
+     * Magic formula for non-autoincrementing integer primary keys
+     *
+     * If a table has a single integer column as its primary key, DB_DataObject
+     * assumes that the column is auto-incrementing and makes a sequence table
+     * to do this incrementation. Since we don't need this for our class, we
+     * overload this method and return the magic formula that DB_DataObject needs.
+     *
+     * @return array magic three-false array that stops auto-incrementing.
+     */
+
+    function sequenceKey()
+    {
+        return array(false, false, false);
+    }
+
+    /**
+     * Save a mapping between a remote Yammer and local imported user.
+     *
+     * @param integer $user_id ID of the status in StatusNet
+     * @param integer $orig_id ID of the notice in Yammer
+     *
+     * @return Yammer_common new object for this value
+     */
+
+    protected static function doRecord($class, $field, $orig_id, $local_id)
+    {
+        $map = parent::staticGet($class, 'id', $orig_id);
+
+        if (!empty($map)) {
+            return $map;
+        }
+
+        $map = parent::staticGet($class, $field, $local_id);
+
+        if (!empty($map)) {
+            return $map;
+        }
+
+        common_debug("Mapping Yammer $field {$orig_id} to local $field {$local_id}");
+
+        $map = new $class();
+
+        $map->id = $orig_id;
+        $map->$field = $local_id;
+        $map->created = common_sql_now();
+
+        $map->insert();
+
+        return $map;
+    }
+}
diff --git a/plugins/YammerImport/classes/Yammer_group.php b/plugins/YammerImport/classes/Yammer_group.php
new file mode 100644
index 0000000000..4e7a6ebd03
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_group.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * Data class for remembering Yammer import mappings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class Yammer_group extends Yammer_common
+{
+    public $__table = 'yammer_group'; // table name
+    public $__field = 'group_id';     // field to map to
+    public $group_id;                 // int
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup
+     * @param mixed  $v Value to lookup
+     *
+     * @return Yammer_group object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Yammer_group', $k, $v);
+    }
+
+    /**
+     * Return schema definition to set this table up in onCheckSchema
+     */
+
+    static function schemaDef()
+    {
+        return self::doSchemaDef('group_id');
+    }
+
+    /**
+     * Save a mapping between a remote Yammer and local imported group.
+     *
+     * @param integer $orig_id ID of the notice in Yammer
+     * @param integer $group_id ID of the status in StatusNet
+     *
+     * @return Yammer_group new object for this value
+     */
+
+    static function record($orig_id, $group_id)
+    {
+        return self::doRecord('Yammer_group', 'group_id', $orig_id, $group_id);
+    }
+}
diff --git a/plugins/YammerImport/classes/Yammer_notice.php b/plugins/YammerImport/classes/Yammer_notice.php
new file mode 100644
index 0000000000..0f63db6303
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_notice.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * Data class for remembering Yammer import mappings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class Yammer_notice extends Yammer_common
+{
+    public $__table = 'yammer_notice'; // table name
+    public $__field = 'notice_id';     // field to map to
+    public $notice_id;                 // int
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup
+     * @param mixed  $v Value to lookup
+     *
+     * @return Yammer_notice object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Yammer_notice', $k, $v);
+    }
+
+    /**
+     * Return schema definition to set this table up in onCheckSchema
+     */
+
+    static function schemaDef()
+    {
+        return self::doSchemaDef('notice_id');
+    }
+
+    /**
+     * Save a mapping between a remote Yammer and local imported notice.
+     *
+     * @param integer $orig_id ID of the notice in Yammer
+     * @param integer $notice_id ID of the status in StatusNet
+     *
+     * @return Yammer_notice new object for this value
+     */
+
+    static function record($orig_id, $notice_id)
+    {
+        return self::doRecord('Yammer_notice', 'notice_id', $orig_id, $notice_id);
+    }
+}
diff --git a/plugins/YammerImport/classes/Yammer_notice_stub.php b/plugins/YammerImport/classes/Yammer_notice_stub.php
new file mode 100644
index 0000000000..e10300c4c7
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_notice_stub.php
@@ -0,0 +1,183 @@
+<?php
+/**
+ * Data class for remembering Yammer import mappings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Temporary storage for imported Yammer messages between fetching and saving
+ * as local notices.
+ *
+ * The Yammer API only allows us to page down from the most recent items; in
+ * order to start saving the oldest notices first, we have to pull them all
+ * down in reverse chronological order, then go back over them from oldest to
+ * newest and actually save them into our notice table.
+ */
+
+class Yammer_notice_stub extends Memcached_DataObject
+{
+    public $__table = 'yammer_notice_stub'; // table name
+    public $id;                             // int  primary_key not_null
+    public $json_data;                      // text
+    public $created;                        // datetime
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup
+     * @param mixed  $v Value to lookup
+     *
+     * @return Yammer_notice_stub object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Yammer_notice_stub', $k, $v);
+    }
+
+    /**
+     * Return schema definition to set this table up in onCheckSchema
+     */
+    static function schemaDef()
+    {
+        return array(new ColumnDef('id', 'bigint', null,
+                                   false, 'PRI'),
+                     new ColumnDef('json_data', 'text', null,
+                                   false),
+                     new ColumnDef('created', 'datetime', null,
+                                   false));
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * DB_DataObject needs to know something about the table to manipulate
+     * instances. This method provides all the DB_DataObject needs to know.
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('id'           => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     'json_data'    => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
+                     'created'      => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has, since it
+     * won't appear in StatusNet's own keys list. In most cases, this will
+     * simply reference your keyTypes() function.
+     *
+     * @return array list of key field names
+     */
+
+    function keys()
+    {
+        return array_keys($this->keyTypes());
+    }
+
+    /**
+     * return key definitions for Memcached_DataObject
+     *
+     * Our caching system uses the same key definitions, but uses a different
+     * method to get them. This key information is used to store and clear
+     * cached data, so be sure to list any key that will be used for static
+     * lookups.
+     *
+     * @return array associative array of key definitions, field name to type:
+     *         'K' for primary key: for compound keys, add an entry for each component;
+     *         'U' for unique keys: compound keys are not well supported here.
+     */
+
+    function keyTypes()
+    {
+        return array('id' => 'K');
+    }
+
+    /**
+     * Magic formula for non-autoincrementing integer primary keys
+     *
+     * If a table has a single integer column as its primary key, DB_DataObject
+     * assumes that the column is auto-incrementing and makes a sequence table
+     * to do this incrementation. Since we don't need this for our class, we
+     * overload this method and return the magic formula that DB_DataObject needs.
+     *
+     * @return array magic three-false array that stops auto-incrementing.
+     */
+
+    function sequenceKey()
+    {
+        return array(false, false, false);
+    }
+
+    /**
+     * Decode the stored data structure.
+     *
+     * @return mixed
+     */
+    public function getData()
+    {
+        return json_decode($this->json_data, true);
+    }
+
+    /**
+     * Save the native Yammer API representation of a message for the pending
+     * import. Since they come in in reverse chronological order, we need to
+     * record them all as stubs and then go through from the beginning and
+     * save them as native notices, or we'll lose ordering and threading
+     * data.
+     *
+     * @param integer $orig_id ID of the notice on Yammer
+     * @param array $data the message record fetched out of Yammer API returnd data
+     *
+     * @return Yammer_notice_stub new object for this value
+     */
+
+    static function record($orig_id, $data)
+    {
+        common_debug("Recording Yammer message stub {$orig_id} for pending import...");
+
+        $stub = new Yammer_notice_stub();
+
+        $stub->id = $orig_id;
+        $stub->json_data = json_encode($data);
+        $stub->created = common_sql_now();
+
+        $stub->insert();
+
+        return $stub;
+    }
+}
diff --git a/plugins/YammerImport/classes/Yammer_state.php b/plugins/YammerImport/classes/Yammer_state.php
new file mode 100644
index 0000000000..2f1fd7780b
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_state.php
@@ -0,0 +1,153 @@
+<?php
+/**
+ * Data class for remembering Yammer import state
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class Yammer_state extends Memcached_DataObject
+{
+    public $__table = 'yammer_state'; // table name
+    public $id;                       // int  primary_key not_null
+    public $state;                    // import state key
+    public $oauth_token;              // actual oauth token! clear when import is done?
+    public $oauth_secret;             // actual oauth secret! clear when import is done?
+    public $users_page;               // last page of users we've fetched
+    public $groups_page;              // last page of groups we've fetched
+    public $messages_oldest;          // oldest message ID we've fetched
+    public $messages_newest;          // newest message ID we've imported
+    public $created;                  // datetime
+    public $modified;                 // datetime
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup
+     * @param mixed  $v Value to lookup
+     *
+     * @return Yammer_state object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Yammer_state', $k, $v);
+    }
+
+    /**
+     * Return schema definition to set this table up in onCheckSchema
+     */
+    static function schemaDef()
+    {
+        return array(new ColumnDef('id', 'int', null,
+                                   false, 'PRI'),
+                     new ColumnDef('state', 'text'),
+                     new ColumnDef('oauth_token', 'text'),
+                     new ColumnDef('oauth_secret', 'text'),
+                     new ColumnDef('users_page', 'int'),
+                     new ColumnDef('groups_page', 'int'),
+                     new ColumnDef('messages_oldest', 'bigint'),
+                     new ColumnDef('messages_newest', 'bigint'),
+                     new ColumnDef('created', 'datetime'),
+                     new ColumnDef('modified', 'datetime'));
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * DB_DataObject needs to know something about the table to manipulate
+     * instances. This method provides all the DB_DataObject needs to know.
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('id'              => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     'state'           => DB_DATAOBJECT_STR,
+                     'oauth_token'     => DB_DATAOBJECT_STR,
+                     'oauth_secret'    => DB_DATAOBJECT_STR,
+                     'users_page'      => DB_DATAOBJECT_INT,
+                     'groups_page'     => DB_DATAOBJECT_INT,
+                     'messages_oldest' => DB_DATAOBJECT_INT,
+                     'messages_newest' => DB_DATAOBJECT_INT,
+                     'created'         => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has, since it
+     * won't appear in StatusNet's own keys list. In most cases, this will
+     * simply reference your keyTypes() function.
+     *
+     * @return array list of key field names
+     */
+
+    function keys()
+    {
+        return array_keys($this->keyTypes());
+    }
+
+    /**
+     * return key definitions for Memcached_DataObject
+     *
+     * Our caching system uses the same key definitions, but uses a different
+     * method to get them. This key information is used to store and clear
+     * cached data, so be sure to list any key that will be used for static
+     * lookups.
+     *
+     * @return array associative array of key definitions, field name to type:
+     *         'K' for primary key: for compound keys, add an entry for each component;
+     *         'U' for unique keys: compound keys are not well supported here.
+     */
+
+    function keyTypes()
+    {
+        return array('id' => 'K');
+    }
+
+    /**
+     * Magic formula for non-autoincrementing integer primary keys
+     *
+     * If a table has a single integer column as its primary key, DB_DataObject
+     * assumes that the column is auto-incrementing and makes a sequence table
+     * to do this incrementation. Since we don't need this for our class, we
+     * overload this method and return the magic formula that DB_DataObject needs.
+     *
+     * @return array magic three-false array that stops auto-incrementing.
+     */
+
+    function sequenceKey()
+    {
+        return array(false, false, false);
+    }
+}
diff --git a/plugins/YammerImport/classes/Yammer_user.php b/plugins/YammerImport/classes/Yammer_user.php
new file mode 100644
index 0000000000..f6fcd6c3cb
--- /dev/null
+++ b/plugins/YammerImport/classes/Yammer_user.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * Data class for remembering Yammer import mappings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Brion Vibber <brion@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+class Yammer_user extends Yammer_common
+{
+    public $__table = 'yammer_user'; // table name
+    public $__field = 'user_id';     // field to map to
+    public $user_id;                 // int
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup
+     * @param mixed  $v Value to lookup
+     *
+     * @return Yammer_user object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Yammer_user', $k, $v);
+    }
+
+    /**
+     * Return schema definition to set this table up in onCheckSchema
+     */
+
+    static function schemaDef()
+    {
+        return self::doSchemaDef('user_id');
+    }
+
+    /**
+     * Save a mapping between a remote Yammer and local imported user.
+     *
+     * @param integer $orig_id ID of the notice in Yammer
+     * @param integer $user_id ID of the status in StatusNet
+     *
+     * @return Yammer_user new object for this value
+     */
+
+    static function record($orig_id, $user_id)
+    {
+        return self::doRecord('Yammer_user', 'user_id', $orig_id, $user_id);
+    }
+}
diff --git a/plugins/YammerImport/css/admin.css b/plugins/YammerImport/css/admin.css
new file mode 100644
index 0000000000..9c99a0b880
--- /dev/null
+++ b/plugins/YammerImport/css/admin.css
@@ -0,0 +1,55 @@
+.yammer-import {
+    padding: 16px;
+}
+
+.import-step {
+    padding: 8px;
+}
+.import-label {
+    font-weight: bold;
+}
+.import-status {
+    margin-left: 20px;
+    padding-left: 20px;
+}
+
+
+.waiting {
+    color: #888;
+}
+
+.progress {
+    background-color: white;
+    border: solid 1px blue;
+    border-radius: 8px;
+    -moz-border-radius: 8px;
+    -webkit-border-radius: 8px;
+    -opera-border-radius: 8px;
+}
+
+.progress .import-label {
+    color: blue;
+}
+
+.progress .import-status {
+    background-image: url(icon_processing.gif);
+    background-repeat: no-repeat;
+}
+
+.complete {
+    color: black;
+}
+
+.complete .import-status {
+    background-image: url(done.png);
+    background-repeat: no-repeat;
+}
+
+.import-step-done .import-status {
+    /* override */
+    background: none !important;
+}
+
+.magiclink {
+    margin-left: 40px;
+}
\ No newline at end of file
diff --git a/plugins/YammerImport/css/done.png b/plugins/YammerImport/css/done.png
new file mode 100644
index 0000000000..1f3f411501
Binary files /dev/null and b/plugins/YammerImport/css/done.png differ
diff --git a/plugins/YammerImport/css/icon_processing.gif b/plugins/YammerImport/css/icon_processing.gif
new file mode 100644
index 0000000000..d0bce15423
Binary files /dev/null and b/plugins/YammerImport/css/icon_processing.gif differ
diff --git a/plugins/YammerImport/lib/sn_yammerclient.php b/plugins/YammerImport/lib/sn_yammerclient.php
new file mode 100644
index 0000000000..5da1cc5e7e
--- /dev/null
+++ b/plugins/YammerImport/lib/sn_yammerclient.php
@@ -0,0 +1,246 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Basic client class for Yammer's OAuth/JSON API.
+ * 
+ * @package YammerImportPlugin
+ * @author Brion Vibber <brion@status.net>
+ */
+class SN_YammerClient
+{
+    protected $apiBase = "https://www.yammer.com";
+    protected $consumerKey, $consumerSecret;
+    protected $token, $tokenSecret, $verifier;
+
+    public function __construct($consumerKey, $consumerSecret, $token=null, $tokenSecret=null)
+    {
+        $this->consumerKey = $consumerKey;
+        $this->consumerSecret = $consumerSecret;
+        $this->token = $token;
+        $this->tokenSecret = $tokenSecret;
+    }
+
+    /**
+     * Make an HTTP GET request with OAuth headers and return an HTTPResponse
+     * with the returned body and codes.
+     *
+     * @param string $url
+     * @return HTTPResponse
+     *
+     * @throws Exception on low-level network error
+     */
+    protected function httpGet($url)
+    {
+        $headers = array('Authorization: ' . $this->authHeader());
+
+        $client = HTTPClient::start();
+        return $client->get($url, $headers);
+    }
+
+    /**
+     * Make an HTTP GET request with OAuth headers and return the response body
+     * on success.
+     *
+     * @param string $url
+     * @return string
+     *
+     * @throws Exception on low-level network or HTTP error
+     */
+    public function fetchUrl($url)
+    {
+        $response = $this->httpGet($url);
+        if ($response->isOk()) {
+            return $response->getBody();
+        } else {
+            throw new Exception("Yammer API returned HTTP code " . $response->getStatus() . ': ' . $response->getBody());
+        }
+    }
+
+    /**
+     * Make an HTTP hit with OAuth headers and return the response body on success.
+     *
+     * @param string $path URL chunk for the API method
+     * @param array $params
+     * @return string
+     *
+     * @throws Exception on low-level network or HTTP error
+     */
+    protected function fetchApi($path, $params=array())
+    {
+        $url = $this->apiBase . '/' . $path;
+        if ($params) {
+            $url .= '?' . http_build_query($params, null, '&');
+        }
+        return $this->fetchUrl($url);
+    }
+
+    /**
+     * Hit the main Yammer API point and decode returned JSON data.
+     *
+     * @param string $method
+     * @param array $params
+     * @return array from JSON data
+     *
+     * @throws Exception for HTTP error or bad JSON return
+     */
+    public function api($method, $params=array())
+    {
+        $body = $this->fetchApi("api/v1/$method.json", $params);
+        $data = json_decode($body, true);
+        if ($data === null) {
+            common_log(LOG_ERR, "Invalid JSON response from Yammer API: " . $body);
+            throw new Exception("Invalid JSON response from Yammer API");
+        }
+        return $data;
+    }
+
+    /**
+     * Build an Authorization header value from the keys we have available.
+     */
+    protected function authHeader()
+    {
+        // token
+        // token_secret
+        $params = array('realm' => '',
+                        'oauth_consumer_key' => $this->consumerKey,
+                        'oauth_signature_method' => 'PLAINTEXT',
+                        'oauth_timestamp' => time(),
+                        'oauth_nonce' => time(),
+                        'oauth_version' => '1.0');
+        if ($this->token) {
+            $params['oauth_token'] = $this->token;
+        }
+        if ($this->tokenSecret) {
+            $params['oauth_signature'] = $this->consumerSecret . '&' . $this->tokenSecret;
+        } else {
+            $params['oauth_signature'] = $this->consumerSecret . '&';
+        }
+        if ($this->verifier) {
+            $params['oauth_verifier'] = $this->verifier;
+        }
+        $parts = array_map(array($this, 'authHeaderChunk'), array_keys($params), array_values($params));
+        return 'OAuth ' . implode(', ', $parts);
+    }
+
+    /**
+     * Encode a key-value pair for use in an authentication header.
+     *
+     * @param string $key
+     * @param string $val
+     * @return string
+     */
+    protected function authHeaderChunk($key, $val)
+    {
+        return urlencode($key) . '="' . urlencode($val) . '"';
+    }
+
+    /**
+     * Ask the Yammer server for a request token, which can be passed on
+     * to authorizeUrl() for the user to start the authentication process.
+     *
+     * @return array of oauth return data; should contain nice things
+     */
+    public function requestToken()
+    {
+        if ($this->token || $this->tokenSecret) {
+            throw new Exception("Requesting a token, but already set up with a token");
+        }
+        $data = $this->fetchApi('oauth/request_token');
+        $arr = array();
+        parse_str($data, $arr);
+        return $arr;
+    }
+
+    /**
+     * Get a final access token from the verifier/PIN code provided to
+     * the user from Yammer's auth pages.
+     *
+     * @return array of oauth return data; should contain nice things
+     */
+    public function accessToken($verifier)
+    {
+        $this->verifier = $verifier;
+        $data = $this->fetchApi('oauth/access_token');
+        $this->verifier = null;
+        $arr = array();
+        parse_str($data, $arr);
+        return $arr;
+    }
+
+    /**
+     * Give the URL to send users to to authorize a new app setup.
+     *
+     * @param string $token as returned from accessToken()
+     * @return string URL
+     */
+    public function authorizeUrl($token)
+    {
+        return $this->apiBase . '/oauth/authorize?oauth_token=' . urlencode($token);
+    }
+
+    /**
+     * High-level API hit: fetch all messages in the network (up to 20 at a time).
+     * Return data is the full JSON array returned, including meta and references
+     * sections.
+     *
+     * The matching messages themselves will be in the 'messages' item within.
+     *
+     * @param array $options optional set of additional params for the request.
+     * @return array
+     *
+     * @throws Exception on low-level or HTTP error
+     */
+    public function messages($params=array())
+    {
+        return $this->api('messages', $params);
+    }
+
+    /**
+     * High-level API hit: fetch all users in the network (up to 50 at a time).
+     * Return data is the full JSON array returned, listing user items.
+     *
+     * The matching messages themselves will be in the 'users' item within.
+     *
+     * @param array $options optional set of additional params for the request.
+     * @return array of JSON-sourced user data arrays
+     *
+     * @throws Exception on low-level or HTTP error
+     */
+    public function users($params=array())
+    {
+        return $this->api('users', $params);
+    }
+
+    /**
+     * High-level API hit: fetch all groups in the network (up to 20 at a time).
+     * Return data is the full JSON array returned, listing user items.
+     *
+     * The matching messages themselves will be in the 'users' item within.
+     *
+     * @param array $options optional set of additional params for the request.
+     * @return array of JSON-sourced user data arrays
+     *
+     * @throws Exception on low-level or HTTP error
+     */
+    public function groups($params=array())
+    {
+        return $this->api('groups', $params);
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerapikeyform.php b/plugins/YammerImport/lib/yammerapikeyform.php
new file mode 100644
index 0000000000..b2acec4ede
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerapikeyform.php
@@ -0,0 +1,112 @@
+<?php
+
+class YammerApikeyForm extends Form
+{
+    private $runner;
+
+    function __construct($out)
+    {
+        parent::__construct($out);
+        $this->runner = $runner;
+    }
+
+    /**
+     * ID of the form
+     *
+     * @return int ID of the form
+     */
+
+    function id()
+    {
+        return 'yammer-apikey-form';
+    }
+
+
+    /**
+     * class of the form
+     *
+     * @return string of the form class
+     */
+
+    function formClass()
+    {
+        return 'form_yammer_apikey form_settings';
+    }
+
+
+    /**
+     * Action of the form
+     *
+     * @return string URL of the action
+     */
+
+    function action()
+    {
+        return common_local_url('yammeradminpanel');
+    }
+
+
+    /**
+     * Legend of the Form
+     *
+     * @return void
+     */
+    function formLegend()
+    {
+        $this->out->element('legend', null, _m('Yammer API registration'));
+    }
+
+    /**
+     * Data elements of the form
+     *
+     * @return void
+     */
+
+    function formData()
+    {
+        $this->out->hidden('subaction', 'apikey');
+
+        $this->out->elementStart('fieldset');
+
+        $this->out->elementStart('p');
+        $this->out->text(_m('Before we can connect to your Yammer network, ' .
+                            'you will need to register the importer as an ' .
+                            'application authorized to pull data on your behalf. ' .
+                            'This registration will work only for your own network. ' .
+                            'Follow this link to register the app at Yammer; ' .
+                            'you will be prompted to log in if necessary:'));
+        $this->out->elementEnd('p');
+
+        $this->out->elementStart('p', array('class' => 'magiclink'));
+        $this->out->element('a',
+            array('href' => 'https://www.yammer.com/client_applications/new',
+                  'target' => '_blank'),
+            _m('Open Yammer application registration form'));
+        $this->out->elementEnd('p');
+
+        $this->out->element('p', array(), _m('Copy the consumer key and secret you are given into the form below:'));
+
+        $this->out->elementStart('ul', array('class' => 'form_data'));
+        $this->out->elementStart('li');
+        $this->out->input('consumer_key', _m('Consumer key:'), common_config('yammer', 'consumer_key'));
+        $this->out->elementEnd('li');
+        $this->out->elementStart('li');
+        $this->out->input('consumer_secret', _m('Consumer secret:'), common_config('yammer', 'consumer_secret'));
+        $this->out->elementEnd('li');
+        $this->out->elementEnd('ul');
+
+        $this->out->submit('submit', _m('Save'), 'submit', null, _m('Save these consumer keys'));
+
+        $this->out->elementEnd('fieldset');
+    }
+
+    /**
+     * Action elements
+     *
+     * @return void
+     */
+
+    function formActions()
+    {
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerauthinitform.php b/plugins/YammerImport/lib/yammerauthinitform.php
new file mode 100644
index 0000000000..9f48fd82a5
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerauthinitform.php
@@ -0,0 +1,76 @@
+<?php
+
+class YammerAuthInitForm extends Form
+{
+    /**
+     * ID of the form
+     *
+     * @return int ID of the form
+     */
+
+    function id()
+    {
+        return 'yammer-auth-init-form';
+    }
+
+
+    /**
+     * class of the form
+     *
+     * @return string of the form class
+     */
+
+    function formClass()
+    {
+        return 'form_yammer_auth_init form_settings';
+    }
+
+
+    /**
+     * Action of the form
+     *
+     * @return string URL of the action
+     */
+
+    function action()
+    {
+        return common_local_url('yammeradminpanel');
+    }
+
+
+    /**
+     * Legend of the Form
+     *
+     * @return void
+     */
+    function formLegend()
+    {
+        $this->out->element('legend', null, _m('Connect to Yammer'));
+    }
+
+    /**
+     * Data elements of the form
+     *
+     * @return void
+     */
+
+    function formData()
+    {
+        $this->out->hidden('subaction', 'authinit');
+
+        $this->out->elementStart('fieldset');
+        $this->out->submit('submit', _m('Start authentication'), 'submit', null, _m('Request authorization to connect to Yammer account'));
+        $this->out->submit('change-apikey', _m('Change API key'));
+        $this->out->elementEnd('fieldset');
+    }
+
+    /**
+     * Action elements
+     *
+     * @return void
+     */
+
+    function formActions()
+    {
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerauthverifyform.php b/plugins/YammerImport/lib/yammerauthverifyform.php
new file mode 100644
index 0000000000..e119be96f7
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerauthverifyform.php
@@ -0,0 +1,111 @@
+<?php
+
+class YammerAuthVerifyForm extends Form
+{
+    private $runner;
+
+    function __construct($out, YammerRunner $runner)
+    {
+        parent::__construct($out);
+        $this->runner = $runner;
+    }
+
+    /**
+     * ID of the form
+     *
+     * @return int ID of the form
+     */
+
+    function id()
+    {
+        return 'yammer-auth-verify-form';
+    }
+
+
+    /**
+     * class of the form
+     *
+     * @return string of the form class
+     */
+
+    function formClass()
+    {
+        return 'form_yammer_auth_verify form_settings';
+    }
+
+
+    /**
+     * Action of the form
+     *
+     * @return string URL of the action
+     */
+
+    function action()
+    {
+        return common_local_url('yammeradminpanel');
+    }
+
+
+    /**
+     * Legend of the Form
+     *
+     * @return void
+     */
+    function formLegend()
+    {
+        $this->out->element('legend', null, _m('Connect to Yammer'));
+    }
+
+    /**
+     * Data elements of the form
+     *
+     * @return void
+     */
+
+    function formData()
+    {
+        $this->out->hidden('subaction', 'authverify');
+
+        $this->out->elementStart('fieldset');
+
+        $this->out->elementStart('p');
+        $this->out->text(_m('Follow this link to confirm authorization at Yammer; you will be prompted to log in if necessary:'));
+        $this->out->elementEnd('p');
+
+        // iframe would be nice to avoid leaving -- since they don't seem to have callback url O_O
+        /*
+        $this->out->element('iframe', array('id' => 'yammer-oauth',
+                                            'src' => $this->runner->getAuthUrl()));
+        */
+        // yeah, it ignores the callback_url
+        // soo... crappy link. :(
+
+        $this->out->elementStart('p', array('class' => 'magiclink'));
+        $this->out->element('a',
+            array('href' => $this->runner->getAuthUrl(),
+                  'target' => '_blank'),
+            _m('Open Yammer authentication window'));
+        $this->out->elementEnd('p');
+        
+        $this->out->element('p', array(), _m('Copy the verification code you are given below:'));
+
+        $this->out->elementStart('ul', array('class' => 'form_data'));
+        $this->out->elementStart('li');
+        $this->out->input('verify_token', _m('Verification code:'));
+        $this->out->elementEnd('li');
+        $this->out->elementEnd('ul');
+        
+        $this->out->submit('submit', _m('Continue'), 'submit', null, _m('Save code and begin import'));
+        $this->out->elementEnd('fieldset');
+    }
+
+    /**
+     * Action elements
+     *
+     * @return void
+     */
+
+    function formActions()
+    {
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerimporter.php b/plugins/YammerImport/lib/yammerimporter.php
new file mode 100644
index 0000000000..0425b8b04e
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerimporter.php
@@ -0,0 +1,456 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Basic client class for Yammer's OAuth/JSON API.
+ *
+ * @package YammerImportPlugin
+ * @author Brion Vibber <brion@status.net>
+ */
+class YammerImporter
+{
+    protected $client;
+
+    function __construct(SN_YammerClient $client)
+    {
+        $this->client = $client;
+    }
+
+    /**
+     * Load or create an imported profile from Yammer data.
+     * 
+     * @param object $item loaded JSON data for Yammer importer
+     * @return Profile
+     */
+    function importUser($item)
+    {
+        $data = $this->prepUser($item);
+
+        $profileId = $this->findImportedUser($data['orig_id']);
+        if ($profileId) {
+            return Profile::staticGet('id', $profileId);
+        } else {
+            $user = User::register($data['options']);
+            $profile = $user->getProfile();
+            if ($data['avatar']) {
+                try {
+                    $this->saveAvatar($data['avatar'], $profile);
+                } catch (Exception $e) {
+                    common_log(LOG_ERR, "Error importing Yammer avatar: " . $e->getMessage());
+                }
+            }
+            $this->recordImportedUser($data['orig_id'], $profile->id);
+            return $profile;
+        }
+    }
+
+    /**
+     * Load or create an imported group from Yammer data.
+     *
+     * @param object $item loaded JSON data for Yammer importer
+     * @return User_group
+     */
+    function importGroup($item)
+    {
+        $data = $this->prepGroup($item);
+
+        $groupId = $this->findImportedGroup($data['orig_id']);
+        if ($groupId) {
+            return User_group::staticGet('id', $groupId);
+        } else {
+            $group = User_group::register($data['options']);
+            if ($data['avatar']) {
+                try {
+                    $this->saveAvatar($data['avatar'], $group);
+                } catch (Exception $e) {
+                    common_log(LOG_ERR, "Error importing Yammer avatar: " . $e->getMessage());
+                }
+            }
+            $this->recordImportedGroup($data['orig_id'], $group->id);
+            return $group;
+        }
+    }
+
+    /**
+     * Load or create an imported notice from Yammer data.
+     *
+     * @param object $item loaded JSON data for Yammer importer
+     * @return Notice
+     */
+    function importNotice($item)
+    {
+        $data = $this->prepNotice($item);
+
+        $noticeId = $this->findImportedNotice($data['orig_id']);
+        if ($noticeId) {
+            return Notice::staticGet('id', $noticeId);
+        } else {
+            $content = $data['content'];
+            $user = User::staticGet($data['profile']);
+
+            // Fetch file attachments and add the URLs...
+            $uploads = array();
+            foreach ($data['attachments'] as $url) {
+                try {
+                    $upload = $this->saveAttachment($url, $user);
+                    $content .= ' ' . $upload->shortUrl();
+                    $uploads[] = $upload;
+                } catch (Exception $e) {
+                    common_log(LOG_ERR, "Error importing Yammer attachment: " . $e->getMessage());
+                }
+            }
+
+            // Here's the meat! Actually save the dang ol' notice.
+            $notice = Notice::saveNew($user->id,
+                                      $content,
+                                      $data['source'],
+                                      $data['options']);
+
+            // Save "likes" as favorites...
+            foreach ($data['faves'] as $nickname) {
+                $user = User::staticGet('nickname', $nickname);
+                if ($user) {
+                    Fave::addNew($user->getProfile(), $notice);
+                }
+            }
+
+            // And finally attach the upload records...
+            foreach ($uploads as $upload) {
+                $upload->attachToNotice($notice);
+            }
+            $this->recordImportedNotice($data['orig_id'], $notice->id);
+            return $notice;
+        }
+    }
+
+    /**
+     * Pull relevant info out of a Yammer data record for a user import.
+     *
+     * @param array $item
+     * @return array
+     */
+    function prepUser($item)
+    {
+        if ($item['type'] != 'user') {
+            throw new Exception('Wrong item type sent to Yammer user import processing.');
+        }
+
+        $origId = $item['id'];
+        $origUrl = $item['url'];
+
+        // @fixme check username rules?
+
+        $options['nickname'] = $item['name'];
+        $options['fullname'] = trim($item['full_name']);
+
+        // Avatar... this will be the "_small" variant.
+        // Remove that (pre-extension) suffix to get the orig-size image.
+        $avatar = $item['mugshot_url'];
+
+        // The following info is only available in full data, not in the reference version.
+
+        // There can be extensive contact info, but for now we'll only pull the primary email.
+        if (isset($item['contact'])) {
+            foreach ($item['contact']['email_addresses'] as $addr) {
+                if ($addr['type'] == 'primary') {
+                    $options['email'] = $addr['address'];
+                    $options['email_confirmed'] = true;
+                    break;
+                }
+            }
+        }
+
+        // There can be multiple external URLs; for now pull the first one as home page.
+        if (isset($item['external_urls'])) {
+            foreach ($item['external_urls'] as $url) {
+                if (common_valid_http_url($url)) {
+                    $options['homepage'] = $url;
+                    break;
+                }
+            }
+        }
+
+        // Combine a few bits into the bio...
+        $bio = array();
+        if (!empty($item['job_title'])) {
+            $bio[] = $item['job_title'];
+        }
+        if (!empty($item['summary'])) {
+            $bio[] = $item['summary'];
+        }
+        if (!empty($item['expertise'])) {
+            $bio[] = _m('Expertise:') . ' ' . $item['expertise'];
+        }
+        $options['bio'] = implode("\n\n", $bio);
+
+        // Pull raw location string, may be lookupable
+        if (!empty($item['location'])) {
+            $options['location'] = $item['location'];
+        }
+
+        // Timezone is in format like 'Pacific Time (US & Canada)'
+        // We need to convert that to a zone id. :P
+        // @fixme timezone not yet supported at registration time :)
+        if (!empty($item['timezone'])) {
+            $tz = $this->timezone($item['timezone']);
+            if ($tz) {
+                $options['timezone'] = $tz;
+            }
+        }
+
+        return array('orig_id' => $origId,
+                     'orig_url' => $origUrl,
+                     'avatar' => $avatar,
+                     'options' => $options);
+
+    }
+
+    /**
+     * Pull relevant info out of a Yammer data record for a group import.
+     *
+     * @param array $item
+     * @return array
+     */
+    function prepGroup($item)
+    {
+        if ($item['type'] != 'group') {
+            throw new Exception('Wrong item type sent to Yammer group import processing.');
+        }
+
+        $origId = $item['id'];
+        $origUrl = $item['url'];
+
+        $privacy = $item['privacy']; // Warning! only public groups in SN so far
+
+        $options['nickname'] = $item['name'];
+        $options['fullname'] = $item['full_name'];
+        $options['description'] = $item['description'];
+        $options['created'] = $this->timestamp($item['created_at']);
+
+        $avatar = $item['mugshot_url']; // as with user profiles...
+
+
+        $options['mainpage'] = common_local_url('showgroup',
+                                   array('nickname' => $options['nickname']));
+
+        // @fixme what about admin user for the group?
+        // bio? homepage etc? aliases?
+
+        $options['local'] = true;
+        return array('orig_id' => $origId,
+                     'orig_url' => $origUrl,
+                     'options' => $options,
+                     'avatar' => $avatar);
+    }
+
+    /**
+     * Pull relevant info out of a Yammer data record for a notice import.
+     *
+     * @param array $item
+     * @return array
+     */
+    function prepNotice($item)
+    {
+        if (isset($item['type']) && $item['type'] != 'message') {
+            throw new Exception('Wrong item type sent to Yammer message import processing.');
+        }
+
+        $origId = $item['id'];
+        $origUrl = $item['url'];
+
+        $profile = $this->findImportedUser($item['sender_id']);
+        $content = $item['body']['plain'];
+        $source = 'yammer';
+        $options = array();
+
+        if ($item['replied_to_id']) {
+            $replyTo = $this->findImportedNotice($item['replied_to_id']);
+            if ($replyTo) {
+                $options['reply_to'] = $replyTo;
+            }
+        }
+        $options['created'] = $this->timestamp($item['created_at']);
+
+        if ($item['group_id']) {
+            $groupId = $this->findImportedGroup($item['group_id']);
+            if ($groupId) {
+                $options['groups'] = array($groupId);
+
+                // @fixme if we see a group link inline, don't add this?
+                $group = User_group::staticGet('id', $groupId);
+                if ($group) {
+                    $content .= ' !' . $group->nickname;
+                }
+            }
+        }
+
+        $faves = array();
+        foreach ($item['liked_by']['names'] as $liker) {
+            // "permalink" is the username. wtf?
+            $faves[] = $liker['permalink'];
+        }
+
+        $attachments = array();
+        foreach ($item['attachments'] as $attach) {
+            if ($attach['type'] == 'image' || $attach['type'] == 'file') {
+                $attachments[] = $attach[$attach['type']]['url'];
+            } else {
+                common_log(LOG_WARNING, "Unrecognized Yammer attachment type: " . $attach['type']);
+            }
+        }
+
+        return array('orig_id' => $origId,
+                     'orig_url' => $origUrl,
+                     'profile' => $profile,
+                     'content' => $content,
+                     'source' => $source,
+                     'options' => $options,
+                     'faves' => $faves,
+                     'attachments' => $attachments);
+    }
+
+    private function findImportedUser($origId)
+    {
+        $map = Yammer_user::staticGet('id', $origId);
+        return $map ? $map->user_id : null;
+    }
+
+    private function findImportedGroup($origId)
+    {
+        $map = Yammer_group::staticGet('id', $origId);
+        return $map ? $map->group_id : null;
+    }
+
+    private function findImportedNotice($origId)
+    {
+        $map = Yammer_notice::staticGet('id', $origId);
+        return $map ? $map->notice_id : null;
+    }
+
+    private function recordImportedUser($origId, $userId)
+    {
+        Yammer_user::record($origId, $userId);
+    }
+
+    private function recordImportedGroup($origId, $groupId)
+    {
+        Yammer_group::record($origId, $groupId);
+    }
+
+    private function recordImportedNotice($origId, $noticeId)
+    {
+        Yammer_notice::record($origId, $noticeId);
+    }
+
+    /**
+     * Normalize timestamp format.
+     * @param string $ts
+     * @return string
+     */
+    private function timestamp($ts)
+    {
+        return common_sql_date(strtotime($ts));
+    }
+
+    private function timezone($tz)
+    {
+        // Blaaaaaarf!
+        $known = array('Pacific Time (US & Canada)' => 'America/Los_Angeles',
+                       'Eastern Time (US & Canada)' => 'America/New_York');
+        if (array_key_exists($tz, $known)) {
+            return $known[$tz];
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Download and update given avatar image
+     *
+     * @param string $url
+     * @param mixed $dest either a Profile or User_group object
+     * @throws Exception in various failure cases
+     */
+    private function saveAvatar($url, $dest)
+    {
+        // Yammer API data mostly gives us the small variant.
+        // Try hitting the source image if we can!
+        // @fixme no guarantee of this URL scheme I think.
+        $url = preg_replace('/_small(\..*?)$/', '$1', $url);
+
+        if (!common_valid_http_url($url)) {
+            throw new ServerException(sprintf(_m("Invalid avatar URL %s."), $url));
+        }
+
+        // @fixme this should be better encapsulated
+        // ripped from oauthstore.php (for old OMB client)
+        $temp_filename = tempnam(sys_get_temp_dir(), 'listener_avatar');
+        if (!copy($url, $temp_filename)) {
+            throw new ServerException(sprintf(_m("Unable to fetch avatar from %s."), $url));
+        }
+
+        $id = $dest->id;
+        // @fixme should we be using different ids?
+        $imagefile = new ImageFile($id, $temp_filename);
+        $filename = Avatar::filename($id,
+                                     image_type_to_extension($imagefile->type),
+                                     null,
+                                     common_timestamp());
+        rename($temp_filename, Avatar::path($filename));
+        // @fixme hardcoded chmod is lame, but seems to be necessary to
+        // keep from accidentally saving images from command-line (queues)
+        // that can't be read from web server, which causes hard-to-notice
+        // problems later on:
+        //
+        // http://status.net/open-source/issues/2663
+        chmod(Avatar::path($filename), 0644);
+
+        $dest->setOriginal($filename);
+    }
+
+    /**
+     * Fetch an attachment from Yammer and save it into our system.
+     * Unlike avatars, the attachment URLs are guarded by authentication,
+     * so we need to run the HTTP hit through our OAuth API client.
+     *
+     * @param string $url
+     * @param User $user
+     * @return MediaFile
+     *
+     * @throws Exception on low-level network or HTTP error
+     */
+    private function saveAttachment($url, User $user)
+    {
+        // Fetch the attachment...
+        // WARNING: file must fit in memory here :(
+        $body = $this->client->fetchUrl($url);
+
+        // Save to a temporary file and shove it into our file-attachment space...
+        $temp = tmpfile();
+        fwrite($temp, $body);
+        try {
+            $upload = MediaFile::fromFileHandle($temp, $user);
+            fclose($temp);
+            return $upload;
+        } catch (Exception $e) {
+            fclose($temp);
+            throw $e;
+        }
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerprogressform.php b/plugins/YammerImport/lib/yammerprogressform.php
new file mode 100644
index 0000000000..776efa100f
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerprogressform.php
@@ -0,0 +1,128 @@
+<?php
+
+class YammerProgressForm extends Form
+{
+    /**
+     * ID of the form
+     *
+     * @return string ID of the form
+     */
+    function id()
+    {
+        return 'yammer-progress';
+    }
+
+    /**
+     * class of the form
+     *
+     * @return string class of the form
+     */
+    function formClass()
+    {
+        return 'form_settings';
+    }
+
+    /**
+     * Action of the form
+     *
+     * @return string URL of the action
+     */
+    function action()
+    {
+        return common_local_url('yammeradminpanel');
+    }
+
+    /**
+     * Data elements of the form
+     *
+     * @return void
+     */
+    function formData()
+    {
+        $runner = YammerRunner::init();
+
+        $userCount = $runner->countUsers();
+        $groupCount = $runner->countGroups();
+        $fetchedCount = $runner->countFetchedNotices();
+        $savedCount = $runner->countSavedNotices();
+
+        $labels = array(
+            'init' => array(
+                'label' => _m("Initialize"),
+                'progress' => _m('No import running'),
+                'complete' => _m('Initiated Yammer server connection...'),
+            ),
+            'requesting-auth' => array(
+                'label' => _m('Connect to Yammer'),
+                'progress' => _m('Awaiting authorization...'),
+                'complete' => _m('Connected.'),
+            ),
+            'import-users' => array(
+                'label' => _m('Import user accounts'),
+                'progress' => sprintf(_m("Importing %d user...", "Importing %d users...", $userCount), $userCount),
+                'complete' => sprintf(_m("Imported %d user.", "Imported %d users.", $userCount), $userCount),
+            ),
+            'import-groups' => array(
+                'label' => _m('Import user groups'),
+                'progress' => sprintf(_m("Importing %d group...", "Importing %d groups...", $groupCount), $groupCount),
+                'complete' => sprintf(_m("Imported %d group.", "Imported %d groups.", $groupCount), $groupCount),
+            ),
+            'fetch-messages' => array(
+                'label' => _m('Prepare public notices for import'),
+                'progress' => sprintf(_m("Preparing %d notice...", "Preparing %d notices...", $fetchedCount), $fetchedCount),
+                'complete' => sprintf(_m("Prepared %d notice.", "Prepared %d notices.", $fetchedCount), $fetchedCount),
+            ),
+            'save-messages' => array(
+                'label' => _m('Import public notices'),
+                'progress' => sprintf(_m("Importing %d notice...", "Importing %d notices...", $savedCount), $savedCount),
+                'complete' => sprintf(_m("Imported %d notice.", "Imported %d notices.", $savedCount), $savedCount),
+            ),
+            'done' => array(
+                'label' => _m('Done'),
+                'progress' => sprintf(_m("Import is complete!")),
+                'complete' => sprintf(_m("Import is complete!")),
+            )
+        );
+        $steps = array_keys($labels);
+        $currentStep = array_search($runner->state(), $steps);
+
+        $this->out->elementStart('fieldset', array('class' => 'yammer-import'));
+        $this->out->element('legend', array(), _m('Import status'));
+        foreach ($steps as $step => $state) {
+            if ($state == 'init') {
+                // Don't show 'init', it's boring.
+                continue;
+            }
+            if ($step < $currentStep) {
+                // This step is done
+                $this->progressBar($state,
+                                   'complete',
+                                   $labels[$state]['label'],
+                                   $labels[$state]['complete']);
+            } else if ($step == $currentStep) {
+                // This step is in progress
+                $this->progressBar($state,
+                                   'progress',
+                                   $labels[$state]['label'],
+                                   $labels[$state]['progress']);
+            } else {
+                // This step has not yet been done.
+                $this->progressBar($state,
+                                   'waiting',
+                                   $labels[$state]['label'],
+                                   _m("Waiting..."));
+            }
+        }
+        $this->out->elementEnd('fieldset');
+    }
+
+    private function progressBar($state, $class, $label, $status)
+    {
+        // @fixme prettify ;)
+        $this->out->elementStart('div', array('class' => "import-step import-step-$state $class"));
+        $this->out->element('div', array('class' => 'import-label'), $label);
+        $this->out->element('div', array('class' => 'import-status'), $status);
+        $this->out->elementEnd('div');
+    }
+
+}
diff --git a/plugins/YammerImport/lib/yammerqueuehandler.php b/plugins/YammerImport/lib/yammerqueuehandler.php
new file mode 100644
index 0000000000..acc8073115
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerqueuehandler.php
@@ -0,0 +1,58 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Queue handler for bumping the next chunk of Yammer import activity!
+ *
+ * @package YammerImportPlugin
+ * @author Brion Vibber <brion@status.net>
+ */
+class YammerQueueHandler extends QueueHandler
+{
+    function transport()
+    {
+        return 'yammer';
+    }
+
+    function handle($notice)
+    {
+        $runner = YammerRunner::init();
+        if ($runner->hasWork()) {
+            if ($runner->iterate()) {
+                if ($runner->hasWork()) {
+                    // More to do? Shove us back on the queue...
+                    $runner->startBackgroundImport();
+                }
+                return true;
+            } else {
+                // Something failed?
+                // @fixme should we be trying again here, or should we give warning?
+                return false;
+            }
+        } else {
+            // We're done!
+            common_log(LOG_INFO, "Yammer import has no work to do at this time; discarding.");
+            return true;
+        }
+    }
+}
diff --git a/plugins/YammerImport/lib/yammerrunner.php b/plugins/YammerImport/lib/yammerrunner.php
new file mode 100644
index 0000000000..e0aec0d166
--- /dev/null
+++ b/plugins/YammerImport/lib/yammerrunner.php
@@ -0,0 +1,398 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * State machine for running through Yammer import.
+ *
+ * @package YammerImportPlugin
+ * @author Brion Vibber <brion@status.net>
+ */
+class YammerRunner
+{
+    private $state;
+    private $client;
+    private $importer;
+
+    /**
+     * Normalize our singleton state and give us a YammerRunner object to play with!
+     *
+     * @return YammerRunner
+     */
+    public static function init()
+    {
+        $state = Yammer_state::staticGet('id', 1);
+        if (!$state) {
+            $state = self::initState();
+        }
+        return new YammerRunner($state);
+    }
+
+    private static function initState()
+    {
+        $state = new Yammer_state();
+        $state->id = 1;
+        $state->state = 'init';
+        $state->created = common_sql_now();
+        $state->modified = common_sql_now();
+        $state->insert();
+        return $state;
+    }
+
+    private function __construct($state)
+    {
+        $this->state = $state;
+
+        $this->client = new SN_YammerClient(
+            common_config('yammer', 'consumer_key'),
+            common_config('yammer', 'consumer_secret'),
+            $this->state->oauth_token,
+            $this->state->oauth_secret);
+
+        $this->importer = new YammerImporter($this->client);
+    }
+
+    /**
+     * Check which state we're in
+     *
+     * @return string
+     */
+    public function state()
+    {
+        return $this->state->state;
+    }
+
+    /**
+     * Is the import done, finished, complete, finito?
+     *
+     * @return boolean
+     */
+    public function isDone()
+    {
+        $workStates = array('import-users', 'import-groups', 'fetch-messages', 'save-messages');
+        return ($this->state() == 'done');
+    }
+
+    /**
+     * Check if we have work to do in iterate().
+     *
+     * @return boolean
+     */
+    public function hasWork()
+    {
+        $workStates = array('import-users', 'import-groups', 'fetch-messages', 'save-messages');
+        return in_array($this->state(), $workStates);
+    }
+
+    /**
+     * Blow away any current state!
+     */
+    public function reset()
+    {
+        $this->state->delete();
+        $this->state = self::initState();
+    }
+
+    /**
+     * Start the authentication process! If all goes well, we'll get back a URL.
+     * Have the user visit that URL, log in on Yammer and verify the importer's
+     * permissions. They'll get back a verification code, which needs to be passed
+     * on to saveAuthToken().
+     *
+     * @return string URL
+     */
+    public function requestAuth()
+    {
+        if ($this->state->state != 'init') {
+            throw new ServerException("Cannot request Yammer auth; already there!");
+        }
+
+        $data = $this->client->requestToken();
+
+        $old = clone($this->state);
+        $this->state->state = 'requesting-auth';
+        $this->state->oauth_token = $data['oauth_token'];
+        $this->state->oauth_secret = $data['oauth_token_secret'];
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+
+        return $this->getAuthUrl();
+    }
+
+    /**
+     * When already in requesting-auth state, grab the URL to send the user to
+     * to complete OAuth setup.
+     *
+     * @return string URL
+     */
+    function getAuthUrl()
+    {
+        if ($this->state() == 'requesting-auth') {
+            return $this->client->authorizeUrl($this->state->oauth_token);
+        } else {
+            throw new ServerException('Cannot get Yammer auth URL when not in requesting-auth state!');
+        }
+    }
+
+    /**
+     * Now that the user's given us this verification code from Yammer, we can
+     * request a final OAuth token/secret pair which we can use to access the
+     * API.
+     *
+     * After success here, we'll be ready to move on and run through iterate()
+     * until the import is complete.
+     *
+     * @param string $verifier
+     * @return boolean success
+     */
+    public function saveAuthToken($verifier)
+    {
+        if ($this->state->state != 'requesting-auth') {
+            throw new ServerException("Cannot save auth token in Yammer import state {$this->state->state}");
+        }
+
+        $data = $this->client->accessToken($verifier);
+
+        $old = clone($this->state);
+        $this->state->state = 'import-users';
+        $this->state->oauth_token = $data['oauth_token'];
+        $this->state->oauth_secret = $data['oauth_token_secret'];
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+
+        return true;
+    }
+
+    /**
+     * Once authentication is complete, we need to call iterate() a bunch of times
+     * until state() returns 'done'.
+     *
+     * @return boolean success
+     */
+    public function iterate()
+    {
+        switch($this->state())
+        {
+            case 'init':
+            case 'requesting-auth':
+                // Neither of these should reach our background state!
+                common_log(LOG_ERR, "Non-background YammerImport state '$state->state' during import run!");
+                return false;
+            case 'import-users':
+                return $this->iterateUsers();
+            case 'import-groups':
+                return $this->iterateGroups();
+            case 'fetch-messages':
+                return $this->iterateFetchMessages();
+            case 'save-messages':
+                return $this->iterateSaveMessages();
+            default:
+                common_log(LOG_ERR, "Invalid YammerImport state '$state->state' during import run!");
+                return false;
+        }
+    }
+
+    /**
+     * Trundle through one 'page' return of up to 50 user accounts retrieved
+     * from the Yammer API, importing them as we go.
+     *
+     * When we run out of users, move on to groups.
+     *
+     * @return boolean success
+     */
+    private function iterateUsers()
+    {
+        $old = clone($this->state);
+
+        $page = intval($this->state->users_page) + 1;
+        $data = $this->client->users(array('page' => $page));
+
+        if (count($data) == 0) {
+            common_log(LOG_INFO, "Finished importing Yammer users; moving on to groups.");
+            $this->state->state = 'import-groups';
+        } else {
+            foreach ($data as $item) {
+                $user = $this->importer->importUser($item);
+                common_log(LOG_INFO, "Imported Yammer user " . $item['id'] . " as $user->nickname ($user->id)");
+            }
+            $this->state->users_page = $page;
+        }
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+        return true;
+    }
+
+    /**
+     * Trundle through one 'page' return of up to 20 user groups retrieved
+     * from the Yammer API, importing them as we go.
+     *
+     * When we run out of groups, move on to messages.
+     *
+     * @return boolean success
+     */
+    private function iterateGroups()
+    {
+        $old = clone($this->state);
+
+        $page = intval($this->state->groups_page) + 1;
+        $data = $this->client->groups(array('page' => $page));
+
+        if (count($data) == 0) {
+            common_log(LOG_INFO, "Finished importing Yammer groups; moving on to messages.");
+            $this->state->state = 'fetch-messages';
+        } else {
+            foreach ($data as $item) {
+                $group = $this->importer->importGroup($item);
+                common_log(LOG_INFO, "Imported Yammer group " . $item['id'] . " as $group->nickname ($group->id)");
+            }
+            $this->state->groups_page = $page;
+        }
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+        return true;
+    }
+
+    /**
+     * Trundle through one 'page' return of up to 20 public messages retrieved
+     * from the Yammer API, saving them to our stub table for future import in
+     * correct chronological order.
+     *
+     * When we run out of messages to fetch, move on to saving the messages.
+     *
+     * @return boolean success
+     */
+    private function iterateFetchMessages()
+    {
+        $old = clone($this->state);
+
+        $oldest = intval($this->state->messages_oldest);
+        if ($oldest) {
+            $params = array('older_than' => $oldest);
+        } else {
+            $params = array();
+        }
+        $data = $this->client->messages($params);
+        $messages = $data['messages'];
+
+        if (count($messages) == 0) {
+            common_log(LOG_INFO, "Finished fetching Yammer messages; moving on to save messages.");
+            $this->state->state = 'save-messages';
+        } else {
+            foreach ($messages as $item) {
+                Yammer_notice_stub::record($item['id'], $item);
+                $oldest = $item['id'];
+            }
+            $this->state->messages_oldest = $oldest;
+        }
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+        return true;
+    }
+
+    private function iterateSaveMessages()
+    {
+        $old = clone($this->state);
+
+        $newest = intval($this->state->messages_newest);
+
+        $stub = new Yammer_notice_stub();
+        if ($newest) {
+            $stub->whereAdd('id > ' . $newest);
+        }
+        $stub->limit(20);
+        $stub->orderBy('id');
+        $stub->find();
+        
+        if ($stub->N == 0) {
+            common_log(LOG_INFO, "Finished saving Yammer messages; import complete!");
+            $this->state->state = 'done';
+        } else {
+            while ($stub->fetch()) {
+                $item = $stub->getData();
+                $notice = $this->importer->importNotice($item);
+                common_log(LOG_INFO, "Imported Yammer notice " . $item['id'] . " as $notice->id");
+                $newest = $item['id'];
+            }
+            $this->state->messages_newest = $newest;
+        }
+        $this->state->modified = common_sql_now();
+        $this->state->update($old);
+        return true;
+    }
+
+    /**
+     * Count the number of Yammer users we've mapped into our system!
+     *
+     * @return int
+     */
+    public function countUsers()
+    {
+        $map = new Yammer_user();
+        return $map->count();
+    }
+
+
+    /**
+     * Count the number of Yammer groups we've mapped into our system!
+     *
+     * @return int
+     */
+    public function countGroups()
+    {
+        $map = new Yammer_group();
+        return $map->count();
+    }
+
+
+    /**
+     * Count the number of Yammer notices we've pulled down for pending import...
+     *
+     * @return int
+     */
+    public function countFetchedNotices()
+    {
+        $map = new Yammer_notice_stub();
+        return $map->count();
+    }
+
+
+    /**
+     * Count the number of Yammer notices we've mapped into our system!
+     *
+     * @return int
+     */
+    public function countSavedNotices()
+    {
+        $map = new Yammer_notice();
+        return $map->count();
+    }
+
+    /**
+     * Start running import work in the background queues...
+     */
+    public function startBackgroundImport()
+    {
+        $qm = QueueManager::get();
+        $qm->enqueue('YammerImport', 'yammer');
+    }
+
+}
diff --git a/plugins/YammerImport/scripts/yammer-import.php b/plugins/YammerImport/scripts/yammer-import.php
new file mode 100644
index 0000000000..b4aa921e50
--- /dev/null
+++ b/plugins/YammerImport/scripts/yammer-import.php
@@ -0,0 +1,65 @@
+<?php
+
+if (php_sapi_name() != 'cli') {
+    die('no');
+}
+
+
+define('INSTALLDIR', dirname(dirname(dirname(dirname(__FILE__)))));
+
+$longoptions = array('verify=', 'reset');
+require INSTALLDIR . "/scripts/commandline.inc";
+
+echo "Checking current state...\n";
+$runner = YammerRunner::init();
+
+if (have_option('reset')) {
+    echo "Resetting Yammer import state...\n";
+    $runner->reset();
+    echo "done.\n";
+    exit(0);
+}
+
+switch ($runner->state())
+{
+    case 'init':
+        echo "Requesting authentication to Yammer API...\n";
+        $url = $runner->requestAuth();
+        echo "Log in to Yammer at the following URL and confirm permissions:\n";
+        echo "\n";
+        echo "    $url\n";
+        echo "\n";
+        echo "Pass the resulting code back by running:\n";
+        echo "\n";
+        echo "    php yammer-import.php --verify=####\n";
+        echo "\n";
+        break;
+
+    case 'requesting-auth':
+        if (!have_option('verify')) {
+            echo "Awaiting authentication...\n";
+            echo "\n";
+            echo "If you need to start over, reset the state:\n";
+            echo "\n";
+            echo "    php yammer-import.php --reset\n";
+            echo "\n";
+            exit(1);
+        }
+        echo "Saving final authentication token for Yammer API...\n";
+        $runner->saveAuthToken(get_option_value('verify'));
+        // Fall through...
+
+    default:
+        while ($runner->hasWork()) {
+            echo "... {$runner->state()}\n";
+            if (!$runner->iterate()) {
+                echo "FAIL??!?!?!\n";
+            }
+        }
+        if ($runner->isDone()) {
+            echo "... done.\n";
+        } else {
+            echo "... no more import work scheduled.\n";
+        }
+        break;
+}