diff --git a/classes/Notice.php b/classes/Notice.php
index ac4640534c..3702dbcfa8 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -282,12 +282,6 @@ class Notice extends Memcached_DataObject
 
         $notice->content = $final;
 
-        if (!empty($rendered)) {
-            $notice->rendered = $rendered;
-        } else {
-            $notice->rendered = common_render_content($final, $notice);
-        }
-
         $notice->source = $source;
         $notice->uri = $uri;
         $notice->url = $url;
@@ -315,6 +309,12 @@ class Notice extends Memcached_DataObject
             $notice->location_ns = $location_ns;
         }
 
+        if (!empty($rendered)) {
+            $notice->rendered = $rendered;
+        } else {
+            $notice->rendered = common_render_content($final, $notice);
+        }
+
         if (Event::handle('StartNoticeSave', array(&$notice))) {
 
             // XXX: some of these functions write to the DB
@@ -944,6 +944,8 @@ class Notice extends Memcached_DataObject
                 $reply->profile_id = $user->id;
 
                 $id = $reply->insert();
+
+                self::blow('reply:stream:%d', $user->id);
             }
         }
 
@@ -971,7 +973,10 @@ class Notice extends Memcached_DataObject
 
         $sender = Profile::staticGet($this->profile_id);
 
-        $mentions = common_find_mentions($this->profile_id, $this->content);
+        // @todo ideally this parser information would only
+        // be calculated once.
+
+        $mentions = common_find_mentions($this->content, $this);
 
         $replied = array();
 
diff --git a/lib/common.php b/lib/common.php
index 2dbe3b3c53..546f6bbe4b 100644
--- a/lib/common.php
+++ b/lib/common.php
@@ -22,7 +22,7 @@ if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
 //exit with 200 response, if this is checking fancy from the installer
 if (isset($_REQUEST['p']) && $_REQUEST['p'] == 'check-fancy') {  exit; }
 
-define('STATUSNET_VERSION', '0.9.0beta6');
+define('STATUSNET_VERSION', '0.9.0beta6+bugfix1');
 define('LACONICA_VERSION', STATUSNET_VERSION); // compatibility
 
 define('STATUSNET_CODENAME', 'Stand');
diff --git a/lib/noticelist.php b/lib/noticelist.php
index 28a563d875..88a9252414 100644
--- a/lib/noticelist.php
+++ b/lib/noticelist.php
@@ -540,22 +540,40 @@ class NoticeListItem extends Widget
     function showContext()
     {
         $hasConversation = false;
-        if( !empty($this->notice->conversation)
-            && $this->notice->conversation != $this->notice->id){
-            $hasConversation = true;
-        }else{
-            $conversation = Notice::conversationStream($this->notice->id, 1, 1);
-            if($conversation->N > 0){
+        if (!empty($this->notice->conversation)) {
+            $conversation = Notice::conversationStream(
+                $this->notice->conversation,
+                1,
+                1
+            );
+            if ($conversation->N > 0) {
                 $hasConversation = true;
             }
         }
-        if ($hasConversation){
-            $this->out->text(' ');
-            $convurl = common_local_url('conversation',
-                                         array('id' => $this->notice->conversation));
-            $this->out->element('a', array('href' => $convurl.'#notice-'.$this->notice->id,
-                                           'class' => 'response'),
-                                _('in context'));
+        if ($hasConversation) {
+            $conv = Conversation::staticGet(
+                'id',
+                $this->notice->conversation
+            );
+            $convurl = $conv->uri;
+            if (!empty($convurl)) {
+                $this->out->text(' ');
+                $this->out->element(
+                    'a',
+                    array(
+                    'href' => $convurl.'#notice-'.$this->notice->id,
+                    'class' => 'response'),
+                    _('in context')
+                );
+            } else {
+                $msg = sprintf(
+                    "Couldn't find Conversation ID %d to make 'in context'"
+                    . "link for Notice ID %d",
+                    $this->notice->conversation,
+                    $this->notice->id
+                );
+                common_log(LOG_WARNING, $msg);
+            }
         }
     }
 
diff --git a/lib/util.php b/lib/util.php
index 1231f4c8d1..c7cb4f313e 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -426,14 +426,14 @@ function common_render_content($text, $notice)
 {
     $r = common_render_text($text);
     $id = $notice->profile_id;
-    $r = common_linkify_mentions($id, $r);
+    $r = common_linkify_mentions($r, $notice);
     $r = preg_replace('/(^|[\s\.\,\:\;]+)!([A-Za-z0-9]{1,64})/e', "'\\1!'.common_group_link($id, '\\2')", $r);
     return $r;
 }
 
-function common_linkify_mentions($profile_id, $text)
+function common_linkify_mentions($text, $notice)
 {
-    $mentions = common_find_mentions($profile_id, $text);
+    $mentions = common_find_mentions($text, $notice);
 
     // We need to go through in reverse order by position,
     // so our positions stay valid despite our fudging with the
@@ -487,11 +487,11 @@ function common_linkify_mention($mention)
     return $output;
 }
 
-function common_find_mentions($profile_id, $text)
+function common_find_mentions($text, $notice)
 {
     $mentions = array();
 
-    $sender = Profile::staticGet('id', $profile_id);
+    $sender = Profile::staticGet('id', $notice->profile_id);
 
     if (empty($sender)) {
         return $mentions;
@@ -499,6 +499,30 @@ function common_find_mentions($profile_id, $text)
 
     if (Event::handle('StartFindMentions', array($sender, $text, &$mentions))) {
 
+        // Get the context of the original notice, if any
+
+        $originalAuthor   = null;
+        $originalNotice   = null;
+        $originalMentions = array();
+
+        // Is it a reply?
+
+        if (!empty($notice) && !empty($notice->reply_to)) {
+            $originalNotice = Notice::staticGet('id', $notice->reply_to);
+            if (!empty($originalNotice)) {
+                $originalAuthor = Profile::staticGet('id', $originalNotice->profile_id);
+
+                $ids = $originalNotice->getReplies();
+
+                foreach ($ids as $id) {
+                    $repliedTo = Profile::staticGet('id', $id);
+                    if (!empty($repliedTo)) {
+                        $originalMentions[$repliedTo->nickname] = $repliedTo;
+                    }
+                }
+            }
+        }
+
         preg_match_all('/^T ([A-Z0-9]{1,64}) /',
                        $text,
                        $tmatches,
@@ -514,7 +538,22 @@ function common_find_mentions($profile_id, $text)
         foreach ($matches as $match) {
 
             $nickname = common_canonical_nickname($match[0]);
-            $mentioned = common_relative_profile($sender, $nickname);
+
+            // Try to get a profile for this nickname.
+            // Start with conversation context, then go to
+            // sender context.
+
+            if (!empty($originalAuthor) && $originalAuthor->nickname == $nickname) {
+
+                $mentioned = $originalAuthor;
+
+            } else if (!empty($originalMentions) &&
+                       array_key_exists($nickname, $originalMentions)) {
+
+                $mention = $originalMentions[$nickname];
+            } else {
+                $mentioned = common_relative_profile($sender, $nickname);
+            }
 
             if (!empty($mentioned)) {
 
@@ -849,7 +888,7 @@ function common_relative_profile($sender, $nickname, $dt=null)
     return null;
 }
 
-function common_local_url($action, $args=null, $params=null, $fragment=null)
+function common_local_url($action, $args=null, $params=null, $fragment=null, $addSession=true)
 {
     $r = Router::get();
     $path = $r->build($action, $args, $params, $fragment);
@@ -857,12 +896,12 @@ function common_local_url($action, $args=null, $params=null, $fragment=null)
     $ssl = common_is_sensitive($action);
 
     if (common_config('site','fancy')) {
-        $url = common_path(mb_substr($path, 1), $ssl);
+        $url = common_path(mb_substr($path, 1), $ssl, $addSession);
     } else {
         if (mb_strpos($path, '/index.php') === 0) {
-            $url = common_path(mb_substr($path, 1), $ssl);
+            $url = common_path(mb_substr($path, 1), $ssl, $addSession);
         } else {
-            $url = common_path('index.php'.$path, $ssl);
+            $url = common_path('index.php'.$path, $ssl, $addSession);
         }
     }
     return $url;
@@ -881,7 +920,7 @@ function common_is_sensitive($action)
     return $ssl;
 }
 
-function common_path($relative, $ssl=false)
+function common_path($relative, $ssl=false, $addSession=true)
 {
     $pathpart = (common_config('site', 'path')) ? common_config('site', 'path')."/" : '';
 
@@ -905,7 +944,9 @@ function common_path($relative, $ssl=false)
         }
     }
 
-    $relative = common_inject_session($relative, $serverpart);
+    if ($addSession) {
+        $relative = common_inject_session($relative, $serverpart);
+    }
 
     return $proto.'://'.$serverpart.'/'.$pathpart.$relative;
 }
@@ -1127,14 +1168,15 @@ function common_broadcast_profile(Profile $profile)
 
 function common_profile_url($nickname)
 {
-    return common_local_url('showstream', array('nickname' => $nickname));
+    return common_local_url('showstream', array('nickname' => $nickname),
+                            null, null, false);
 }
 
 // Should make up a reasonable root URL
 
 function common_root_url($ssl=false)
 {
-    $url = common_path('', $ssl);
+    $url = common_path('', $ssl, false);
     $i = strpos($url, '?');
     if ($i !== false) {
         $url = substr($url, 0, $i);
@@ -1419,7 +1461,8 @@ function common_remove_magic_from_request()
 
 function common_user_uri(&$user)
 {
-    return common_local_url('userbyid', array('id' => $user->id));
+    return common_local_url('userbyid', array('id' => $user->id),
+                            null, null, false);
 }
 
 function common_notice_uri(&$notice)
diff --git a/plugins/OStatus/classes/HubSub.php b/plugins/OStatus/classes/HubSub.php
index 1ac181feeb..e599d83a96 100644
--- a/plugins/OStatus/classes/HubSub.php
+++ b/plugins/OStatus/classes/HubSub.php
@@ -99,7 +99,7 @@ class HubSub extends Memcached_DataObject
         return array_keys($this->keyTypes());
     }
 
-    function sequenceKeys()
+    function sequenceKey()
     {
         return array(false, false, false);
     }
diff --git a/plugins/OStatus/classes/Magicsig.php b/plugins/OStatus/classes/Magicsig.php
index 751527c819..96900d8761 100644
--- a/plugins/OStatus/classes/Magicsig.php
+++ b/plugins/OStatus/classes/Magicsig.php
@@ -50,7 +50,11 @@ class Magicsig extends Memcached_DataObject
     public /*static*/ function staticGet($k, $v=null)
     {
         $obj =  parent::staticGet(__CLASS__, $k, $v);
-        return Magicsig::fromString($obj->keypair);
+        if (!empty($obj)) {
+            return Magicsig::fromString($obj->keypair);
+        }
+
+        return $obj;
     }
 
 
@@ -84,6 +88,10 @@ class Magicsig extends Memcached_DataObject
         return array('user_id' => 'K');
     }
 
+    function sequenceKey() {
+        return array(false, false, false);
+    }
+
     function insert()
     {
         $this->keypair = $this->toString();
@@ -173,14 +181,15 @@ class Magicsig extends Memcached_DataObject
         switch ($this->alg) {
 
         case 'RSA-SHA256':
-            return 'sha256';
+            return 'magicsig_sha256';
         }
 
     }
     
     public function sign($bytes)
     {
-        $sig = $this->_rsa->createSign($bytes, null, 'sha256');
+        $hash = $this->getHash();
+        $sig = $this->_rsa->createSign($bytes, null, $hash);
         if ($this->_rsa->isError()) {
             $error = $this->_rsa->getLastError();
             common_log(LOG_DEBUG, 'RSA Error: '. $error->getMessage());
@@ -192,7 +201,8 @@ class Magicsig extends Memcached_DataObject
 
     public function verify($signed_bytes, $signature)
     {
-        $result =  $this->_rsa->validateSign($signed_bytes, $signature, null, 'sha256');
+        $hash = $this->getHash();
+        $result =  $this->_rsa->validateSign($signed_bytes, $signature, null, $hash);
         if ($this->_rsa->isError()) {
             $error = $this->keypair->getLastError();
             common_log(LOG_DEBUG, 'RSA Error: '. $error->getMessage());
@@ -205,7 +215,7 @@ class Magicsig extends Memcached_DataObject
 
 // Define a sha256 function for hashing
 // (Crypt_RSA should really be updated to use hash() )
-function sha256($bytes)
+function magicsig_sha256($bytes)
 {
     return hash('sha256', $bytes);
 }
diff --git a/plugins/OStatus/classes/Ostatus_profile.php b/plugins/OStatus/classes/Ostatus_profile.php
index 35539bff77..7b1aec76ba 100644
--- a/plugins/OStatus/classes/Ostatus_profile.php
+++ b/plugins/OStatus/classes/Ostatus_profile.php
@@ -1288,9 +1288,9 @@ class Ostatus_profile extends Memcached_DataObject
 
         $disco = new Discovery();
 
-        $result = $disco->lookup($addr);
-
-        if (!$result) {
+        try {
+            $result = $disco->lookup($addr);
+        } catch (Exception $e) {
             self::cacheSet(sprintf('ostatus_profile:webfinger:%s', $addr), null);
             return null;
         }
diff --git a/plugins/OStatus/lib/magicenvelope.php b/plugins/OStatus/lib/magicenvelope.php
index f33119b8f7..230d81ba1f 100644
--- a/plugins/OStatus/lib/magicenvelope.php
+++ b/plugins/OStatus/lib/magicenvelope.php
@@ -83,6 +83,28 @@ class MagicEnvelope
             
     }
 
+    public function toXML($env) {
+        $dom = new DOMDocument();
+
+        $envelope = $dom->createElementNS(MagicEnvelope::NS, 'me:env');
+        $envelope->setAttribute('xmlns:me', MagicEnvelope::NS);
+        $data = $dom->createElementNS(MagicEnvelope::NS, 'me:data', $env['data']);
+        $data->setAttribute('type', $env['data_type']);
+        $envelope->appendChild($data);
+        $enc = $dom->createElementNS(MagicEnvelope::NS, 'me:encoding', $env['encoding']);
+        $envelope->appendChild($enc);
+        $alg = $dom->createElementNS(MagicEnvelope::NS, 'me:alg', $env['alg']);
+        $envelope->appendChild($alg);
+        $sig = $dom->createElementNS(MagicEnvelope::NS, 'me:sig', $env['sig']);
+        $envelope->appendChild($sig);
+
+        $dom->appendChild($envelope);
+        
+        
+        return $dom->saveXML();
+    }
+
+    
     public function unfold($env)
     {
         $dom = new DOMDocument();
diff --git a/plugins/OStatus/lib/salmon.php b/plugins/OStatus/lib/salmon.php
index 6e24595441..3d3341bc63 100644
--- a/plugins/OStatus/lib/salmon.php
+++ b/plugins/OStatus/lib/salmon.php
@@ -48,11 +48,14 @@ class Salmon
             return false;
         }
 
-        if (!common_config('ostatus', 'skip_signatures')) {
+        try {
             $xml = $this->createMagicEnv($xml, $actor);
+        } catch (Exception $e) {
+            common_log(LOG_ERR, "Salmon unable to sign: " . $e->getMessage());
+            return false;
         }
 
-        $headers = array('Content-Type: application/atom+xml');
+        $headers = array('Content-Type: application/magic-envelope+xml');
 
         try {
             $client = new HTTPClient();
@@ -72,7 +75,6 @@ class Salmon
 
     public function createMagicEnv($text, $actor)
     {
-        common_log(LOG_DEBUG, "Got actor as : ". print_r($actor, true));
         $magic_env = new MagicEnvelope();
 
         $user = User::staticGet('id', $actor->id);
@@ -84,7 +86,6 @@ class Salmon
                 $magickey = new Magicsig();
                 $magickey->generate($user->id);
             } 
-            common_log(LOG_DEBUG, "Salmon: Loaded key for ". $user->id);
         } else {
             throw new Exception("Salmon invalid actor for signing");
         }
@@ -92,18 +93,17 @@ class Salmon
         try {
             $env = $magic_env->signMessage($text, 'application/atom+xml', $magickey->toString());
         } catch (Exception $e) {
-            common_log(LOG_ERR, "Salmon signing failed: ". $e->getMessage());
             return $text;
         }
-        return $magic_env->unfold($env);
+        return $magic_env->toXML($env);
     }
 
 
-    public function verifyMagicEnv($dom)
+    public function verifyMagicEnv($text)
     {
         $magic_env = new MagicEnvelope();
         
-        $env = $magic_env->fromDom($dom);
+        $env = $magic_env->parse($text);
 
         return $magic_env->verify($env);
     }
diff --git a/plugins/OStatus/lib/salmonaction.php b/plugins/OStatus/lib/salmonaction.php
index a03169101b..fa9dc3b1da 100644
--- a/plugins/OStatus/lib/salmonaction.php
+++ b/plugins/OStatus/lib/salmonaction.php
@@ -41,29 +41,32 @@ class SalmonAction extends Action
             $this->clientError(_m('This method requires a POST.'));
         }
 
-        if (empty($_SERVER['CONTENT_TYPE']) || $_SERVER['CONTENT_TYPE'] != 'application/atom+xml') {
-            $this->clientError(_m('Salmon requires application/atom+xml'));
+        if (empty($_SERVER['CONTENT_TYPE']) || $_SERVER['CONTENT_TYPE'] != 'application/magic-envelope+xml') {
+            $this->clientError(_m('Salmon requires application/magic-envelope+xml'));
         }
 
         $xml = file_get_contents('php://input');
 
-        $dom = DOMDocument::loadXML($xml);
 
+        // Check the signature
+        $salmon = new Salmon;
+        if (!$salmon->verifyMagicEnv($xml)) {
+            common_log(LOG_DEBUG, "Salmon signature verification failed.");
+            $this->clientError(_m('Salmon signature verification failed.'));
+        } else {
+            $magic_env = new MagicEnvelope();
+            $env = $magic_env->parse($xml);
+            $xml = $magic_env->unfold($env);
+        }
+        
+
+        $dom = DOMDocument::loadXML($xml);
         if ($dom->documentElement->namespaceURI != Activity::ATOM ||
             $dom->documentElement->localName != 'entry') {
             common_log(LOG_DEBUG, "Got invalid Salmon post: $xml");
             $this->clientError(_m('Salmon post must be an Atom entry.'));
         }
 
-        // Check the signature
-        $salmon = new Salmon;
-        if (!common_config('ostatus', 'skip_signatures')) {
-            if (!$salmon->verifyMagicEnv($dom)) {
-                common_log(LOG_DEBUG, "Salmon signature verification failed.");
-                $this->clientError(_m('Salmon signature verification failed.'));
-            }
-        }
-
         $this->act = new Activity($dom->documentElement);
         return true;
     }
diff --git a/plugins/RegisterThrottle/RegisterThrottlePlugin.php b/plugins/RegisterThrottle/RegisterThrottlePlugin.php
new file mode 100644
index 0000000000..05709b7807
--- /dev/null
+++ b/plugins/RegisterThrottle/RegisterThrottlePlugin.php
@@ -0,0 +1,249 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * Throttle registration by IP address
+ *
+ * PHP version 5
+ *
+ * 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  Spam
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Throttle registration by IP address
+ *
+ * We a) record IP address of registrants and b) throttle registrations.
+ *
+ * @category  Spam
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ */
+
+class RegisterThrottlePlugin extends Plugin
+{
+    /**
+     * Array of time spans in seconds to limits.
+     *
+     * Default is 3 registrations per hour, 5 per day, 10 per week.
+     */
+
+    public $regLimits = array(604800 => 10, // per week
+                              86400 => 5, // per day
+                              3600 => 3); // per hour
+
+    /**
+     * Database schema setup
+     *
+     * We store user registrations in a table registration_ip.
+     *
+     * @return boolean hook value; true means continue processing, false means stop.
+     */
+
+    function onCheckSchema()
+    {
+        $schema = Schema::get();
+
+        // For storing user-submitted flags on profiles
+
+        $schema->ensureTable('registration_ip',
+                             array(new ColumnDef('user_id', 'integer', null,
+                                                 false, 'PRI'),
+                                   new ColumnDef('ipaddress', 'varchar', 15, false, 'MUL'),
+                                   new ColumnDef('created', 'timestamp', null, false, 'MUL')));
+
+        return true;
+    }
+
+    /**
+     * Load related modules when needed
+     *
+     * @param string $cls Name of the class to be loaded
+     *
+     * @return boolean hook value; true means continue processing, false means stop.
+     */
+
+    function onAutoload($cls)
+    {
+        $dir = dirname(__FILE__);
+
+        switch ($cls)
+        {
+        case 'Registration_ip':
+            include_once $dir . '/'.$cls.'.php';
+            return false;
+        default:
+            return true;
+        }
+    }
+
+    /**
+     * Called when someone tries to register.
+     *
+     * We check the IP here to determine if it goes over any of our
+     * configured limits.
+     *
+     * @param Action $action Action that is being executed
+     *
+     * @return boolean hook value
+     *
+     */
+
+    function onStartRegistrationTry($action)
+    {
+        $ipaddress = $this->_getIpAddress();
+
+        if (empty($ipaddress)) {
+            throw new ServerException(_m('Cannot find IP address.'));
+        }
+
+        foreach ($this->regLimits as $seconds => $limit) {
+
+            $this->debug("Checking $seconds ($limit)");
+
+            $reg = $this->_getNthReg($ipaddress, $limit);
+
+            if (!empty($reg)) {
+                $this->debug("Got a {$limit}th registration.");
+                $regtime = strtotime($reg->created);
+                $now     = time();
+                $this->debug("Comparing {$regtime} to {$now}");
+                if ($now - $regtime < $seconds) {
+                    throw new Exception(_("Too many registrations. Take a break and try again later."));
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Called after someone registers.
+     *
+     * We record the successful registration and IP address.
+     *
+     * @param Action $action Action that is being executed
+     *
+     * @return boolean hook value
+     *
+     */
+
+    function onEndRegistrationTry($action)
+    {
+        $ipaddress = $this->_getIpAddress();
+
+        if (empty($ipaddress)) {
+            throw new ServerException(_m('Cannot find IP address.'));
+        }
+
+        $user = common_current_user();
+
+        if (empty($user)) {
+            throw new ServerException(_m('Cannot find user after successful registration.'));
+        }
+
+        $reg = new Registration_ip();
+
+        $reg->user_id   = $user->id;
+        $reg->ipaddress = $ipaddress;
+
+        $result = $reg->insert();
+
+        if (!$result) {
+            common_log_db_error($reg, 'INSERT', __FILE__);
+            // @todo throw an exception?
+        }
+
+        return true;
+    }
+
+    /**
+     * Check the version of the plugin.
+     *
+     * @param array &$versions Version array.
+     *
+     * @return boolean hook value
+     */
+
+    function onPluginVersion(&$versions)
+    {
+        $versions[] = array('name' => 'RegisterThrottle',
+                            'version' => STATUSNET_VERSION,
+                            'author' => 'Evan Prodromou',
+                            'homepage' => 'http://status.net/wiki/Plugin:RegisterThrottle',
+                            'description' =>
+                            _m('Throttles excessive registration from a single IP.'));
+        return true;
+    }
+
+    /**
+     * Gets the current IP address.
+     *
+     * @return string IP address or null if not found.
+     */
+
+    private function _getIpAddress()
+    {
+        $keys = array('HTTP_X_FORWARDED_FOR',
+                      'CLIENT-IP',
+                      'REMOTE_ADDR');
+
+        foreach ($keys as $k) {
+            if (!empty($_SERVER[$k])) {
+                return $_SERVER[$k];
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Gets the Nth registration with the given IP address.
+     *
+     * @param string  $ipaddress Address to key on
+     * @param integer $n         Nth address
+     *
+     * @return Registration_ip nth registration or null if not found.
+     */
+
+    private function _getNthReg($ipaddress, $n)
+    {
+        $reg = new Registration_ip();
+
+        $reg->ipaddress = $ipaddress;
+
+        $reg->orderBy('created DESC');
+        $reg->limit($n - 1, 1);
+
+        if ($reg->find(true)) {
+            return $reg;
+        } else {
+            return null;
+        }
+    }
+}
diff --git a/plugins/RegisterThrottle/Registration_ip.php b/plugins/RegisterThrottle/Registration_ip.php
new file mode 100644
index 0000000000..7e61d089e7
--- /dev/null
+++ b/plugins/RegisterThrottle/Registration_ip.php
@@ -0,0 +1,124 @@
+<?php
+/**
+ * Data class for storing IP addresses of new registrants.
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@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);
+}
+
+require_once INSTALLDIR . '/classes/Memcached_DataObject.php';
+
+/**
+ * Data class for storing IP addresses of new registrants.
+ *
+ * @category Spam
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ */
+
+class Registration_ip extends Memcached_DataObject
+{
+    public $__table = 'registration_ip';     // table name
+    public $user_id;                         // int(4)  primary_key not_null
+    public $ipaddress;                       // varchar(15)
+    public $created;                         // timestamp
+
+    /**
+     * Get an instance by key
+     *
+     * @param string $k Key to use to lookup (usually 'user_id' for this class)
+     * @param mixed  $v Value to lookup
+     *
+     * @return User_greeting_count object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('Registration_ip', $k, $v);
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('user_id' => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     'ipaddress' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
+                     'created' => DB_DATAOBJECT_MYSQLTIMESTAMP + DB_DATAOBJECT_NOTNULL);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has; this function
+     * defines them.
+     *
+     * @return array key definitions
+     */
+
+    function keys()
+    {
+        return array('user_id' => 'K');
+    }
+
+    /**
+     * return key definitions for Memcached_DataObject
+     *
+     * Our caching system uses the same key definitions, but uses a different
+     * method to get them.
+     *
+     * @return array key definitions
+     */
+
+    function keyTypes()
+    {
+        return $this->keys();
+    }
+
+    /**
+     * 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/theme/base/css/display.css b/theme/base/css/display.css
index 52f97f6b12..f32c57ea45 100644
--- a/theme/base/css/display.css
+++ b/theme/base/css/display.css
@@ -799,8 +799,8 @@ list-style-type:none;
 display:inline;
 }
 .entity_tags li {
-float:left;
-margin-right:11px;
+display:inline;
+margin-right:7px;
 }
 
 .aside .section {