diff --git a/plugins/Gravatar/GravatarPlugin.php b/plugins/Gravatar/GravatarPlugin.php
index dd8ff72176..5fcc79fd51 100644
--- a/plugins/Gravatar/GravatarPlugin.php
+++ b/plugins/Gravatar/GravatarPlugin.php
@@ -183,7 +183,7 @@ class GravatarPlugin extends Plugin
 
     function gravatar_url($email, $size)
     {
-        $url = "http://www.gravatar.com/avatar.php?gravatar_id=".
+        $url = "https://secure.gravatar.com/avatar.php?gravatar_id=".
                 md5(strtolower($email)).
                 "&default=".urlencode(Avatar::defaultImage($size)).
                 "&size=".$size;
diff --git a/plugins/Mapstraction/MapstractionPlugin.php b/plugins/Mapstraction/MapstractionPlugin.php
index c4ba6464ea..08465e0a77 100644
--- a/plugins/Mapstraction/MapstractionPlugin.php
+++ b/plugins/Mapstraction/MapstractionPlugin.php
@@ -125,7 +125,7 @@ class MapstractionPlugin extends Plugin
                                     urlencode($this->apikey)));
             break;
         case 'microsoft':
-            $action->script('http://dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6');
+            $action->script((StatusNet::isHTTPS()?'https':'http') + '://dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6');
             break;
         case 'openlayers':
             // XXX: is this not nice...?
diff --git a/plugins/Recaptcha/RecaptchaPlugin.php b/plugins/Recaptcha/RecaptchaPlugin.php
index 08557cbd84..5a33e7132e 100644
--- a/plugins/Recaptcha/RecaptchaPlugin.php
+++ b/plugins/Recaptcha/RecaptchaPlugin.php
@@ -51,15 +51,6 @@ class RecaptchaPlugin extends Plugin
         }
     }
 
-    function checkssl()
-    {
-        if(common_config('site', 'ssl') === 'sometimes' || common_config('site', 'ssl') === 'always') {
-            return true;
-        }
-        return false;
-    }
-
-
     function onEndRegistrationFormData($action)
     {
         $action->elementStart('li');
@@ -79,7 +70,7 @@ class RecaptchaPlugin extends Plugin
     {
         if (isset($action->recaptchaPluginNeedsOutput) && $action->recaptchaPluginNeedsOutput) {
             // Load the AJAX API
-            if ($this->checkssl()) {
+            if (StatusNet::isHTTPS()) {
                 $url = "https://api-secure.recaptcha.net/js/recaptcha_ajax.js";
             } else {
                 $url = "http://api.recaptcha.net/js/recaptcha_ajax.js";
@@ -120,4 +111,4 @@ class RecaptchaPlugin extends Plugin
                                'captcha to the registration page.'));
         return true;
     }
-}
\ No newline at end of file
+}
diff --git a/plugins/StrictTransportSecurity/README b/plugins/StrictTransportSecurity/README
new file mode 100644
index 0000000000..66f03e95ea
--- /dev/null
+++ b/plugins/StrictTransportSecurity/README
@@ -0,0 +1,21 @@
+The Strict Transport Security plugin implements the Strict Transport Security header, improving the security of HTTPS only sites.
+See http://lists.w3.org/Archives/Public/www-archive/2009Sep/att-0051/draft-hodges-strict-transport-sec-05.plain.html for the specification.
+
+Installation
+============
+add "addPlugin('strictTransportSecurity');"
+to the bottom of your config.php
+
+The plugin will not do anything unless:
+$config['site']['ssl'] is set to 'always'
+$config['site']['path'] is either not set, empty, or '/'
+
+Settings
+========
+max_age (15552000): sets how long to remember the forced HTTPS (seconds) (15552000 seconds is 180 days)
+includeSubDomains (false): if set, then STS will apply to all the sub-domains too.
+
+Example
+=======
+addPlugin('strictTransportSecurity');
+
diff --git a/plugins/StrictTransportSecurity/StrictTransportSecurityPlugin.php b/plugins/StrictTransportSecurity/StrictTransportSecurityPlugin.php
new file mode 100644
index 0000000000..004a627929
--- /dev/null
+++ b/plugins/StrictTransportSecurity/StrictTransportSecurityPlugin.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Plugin to enable Single Sign On via CAS (Central Authentication Service)
+ *
+ * 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  Plugin
+ * @package   StatusNet
+ * @author    Craig Andrews <candrews@integralblue.com>
+ * @copyright 2009 Free Software Foundation, Inc http://www.fsf.org
+ * @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') && !defined('LACONICA')) {
+    exit(1);
+}
+
+class StrictTransportSecurityPlugin extends Plugin
+{
+    public $max_age = 15552000;
+    public $includeSubDomains = false;
+
+    function __construct()
+    {
+        parent::__construct();
+    }
+
+    function onArgsInitialize($args)
+    {
+        $path = common_config('site', 'path');
+        if(common_config('site', 'ssl') == 'always' && ($path == '/' || ! $path )) {
+            header('Strict-Transport-Security: max-age=' . $this->max_age . + ($this->includeSubDomains?'; includeSubDomains':''));
+        }
+    }
+
+    function onPluginVersion(&$versions)
+    {
+        $versions[] = array('name' => 'StrictTransportSecurity',
+                            'version' => STATUSNET_VERSION,
+                            'author' => 'Craig Andrews',
+                            'homepage' => 'http://status.net/wiki/Plugin:StrictTransportSecurity',
+                            'rawdescription' =>
+                            _m('The Strict Transport Security plugin implements the Strict Transport Security header, improving the security of HTTPS only sites.'));
+        return true;
+    }
+}