diff --git a/contrib/favorites/main.php b/contrib/favorites/main.php
new file mode 100644
index 00000000..55f4fc2e
--- /dev/null
+++ b/contrib/favorites/main.php
@@ -0,0 +1,163 @@
+<?php
+/**
+ * Name: Favorites
+ * Author: Daniel Marschall <info@daniel-marschall.de>
+ * License: GPLv2
+ * Description: Allow users to favorite images
+ */
+
+class FavoriteSetEvent extends Event {
+	var $image_id, $user, $do_set;
+
+	public function FavoriteSetEvent($image_id, $user, $do_set) {
+		$this->image_id = $image_id;
+		$this->user = $user;
+		$this->do_set = $do_set;
+	}
+}
+
+class Favorites extends Extension {
+	var $theme;
+
+	public function receive_event($event) {
+		if(is_null($this->theme)) $this->theme = get_theme_object("favorites", "FavoritesTheme");
+
+		if(is_a($event, 'InitExtEvent')) {
+			global $config;
+			if($config->get_int("ext_favorites_version", 0) < 1) {
+				$this->install();
+			}
+		}
+		
+		if(is_a($event, 'DisplayingImageEvent')) {
+			global $user;
+			if(!$user->is_anonymous()) {
+			
+				$user_id = $user->id;				
+				$image_id = $event->image->id;
+				
+				global $database;
+				
+				$is_favorited = false;
+				$sqlresult = $database->execute("SELECT COUNT(*) AS ct FROM user_favorites WHERE user_id = ? AND image_id = ?", array($user_id, $image_id));
+				if(!$sqlresult->EOF)
+				{
+					$is_favorited = $sqlresult->fields['ct'] > 0;
+				}
+			
+				$html = $this->theme->get_voter_html($event->image, $is_favorited);
+			} else {
+				$html = $this->theme->show_anonymous_html($event->image);
+			}
+			$event->page->add_block(new Block("Favorites", $html, "left", 20));
+			
+			$html = $this->theme->show_favorite_marks($this->list_persons_who_have_favorited($event->image));
+
+			$event->page->add_block(new Block("Favorited by", $html, "left", 25));
+		}
+		
+		if(is_a($event, 'PageRequestEvent') && ($event->page_name == "change_favorite")) {
+			if(!$event->user->is_anonymous()) {
+				$image_id = int_escape($_POST['image_id']);
+				if (($_POST['favorite_action'] == "set") || ($_POST['favorite_action'] == "unset")) {
+					send_event(new FavoriteSetEvent($image_id, $event->user, ($_POST['favorite_action'] == "set")));
+				}
+				$event->page->set_mode("redirect");
+				$event->page->set_redirect(make_link("post/view/$image_id"));
+			}
+		}
+		
+		if(is_a($event, 'ImageInfoSetEvent')) {
+			global $user;
+			if (($_POST['favorite_action'] == "set") || ($_POST['favorite_action'] == "unset")) {
+				send_event(new FavoriteSetEvent($event->image_id, $user, ($_POST['favorite_action'] == "set")));
+			}
+		}
+		
+		if(is_a($event, 'FavoriteSetEvent')) {
+			$this->add_vote($event->image_id, $event->user->id, $event->do_set);
+		}
+
+		if(is_a($event, 'ImageDeletionEvent')) {
+			global $database;
+			$database->execute("DELETE FROM user_favorites WHERE image_id=?", array($event->image->id));
+		}
+
+		if(is_a($event, 'ParseLinkTemplateEvent')) {
+			$event->replace('$favorites', $event->image->favorites);
+		}
+
+		if(is_a($event, 'SearchTermParseEvent')) {
+			$matches = array();
+			if(preg_match("/favorites(<|>|<=|>=|=)(\d+)/", $event->term, $matches)) {
+				$cmp = $matches[1];
+				$favorites = $matches[2];
+				$event->set_querylet(new Querylet("favorites $cmp $favorites"));
+			}
+			else if(preg_match("/favorited_by=(.*)/i", $event->term, $matches)) {
+				global $database;
+				$user = $database->get_user_by_name($matches[1]);
+				if(!is_null($user)) {
+					$user_id = $user->id;
+				}
+				else {
+					$user_id = -1;
+				}
+
+				$event->set_querylet(new Querylet("images.id IN (SELECT image_id FROM user_favorites WHERE user_id = $user_id)"));
+			}
+			else if(preg_match("/favorited_by_userno=([0-9]+)/i", $event->term, $matches)) {
+				$user_id = int_escape($matches[1]);
+				$event->set_querylet(new Querylet("images.id IN (SELECT image_id FROM user_favorites WHERE user_id = $user_id)"));
+			}
+		}
+	}
+
+	private function install() {
+		global $database;
+		global $config;
+
+		if($config->get_int("ext_favorites_version") < 1) {
+			$database->Execute("ALTER TABLE images ADD COLUMN favorites INTEGER NOT NULL DEFAULT 0");
+			$database->Execute("CREATE INDEX images__favorites ON images(favorites)");
+			$database->Execute("
+				CREATE TABLE user_favorites (
+					image_id INTEGER NOT NULL,
+					user_id INTEGER NOT NULL,
+					created_at DATETIME NOT NULL,,
+					UNIQUE(image_id, user_id),
+					INDEX(image_id)
+				)
+			");
+			$config->set_int("ext_favorites_version", 1);
+		}
+	}
+
+	private function add_vote($image_id, $user_id, $do_set) {
+		global $database;
+		if ($do_set) {
+			$database->Execute(
+				"INSERT INTO user_favorites(image_id, user_id, created_at) VALUES(?, ?, NOW())",
+				array($image_id, $user_id));
+		} else {
+			$database->Execute(
+				"DELETE FROM user_favorites WHERE image_id = ? AND user_id = ?",
+				array($image_id, $user_id));
+		}
+		$database->Execute(
+			"UPDATE images SET favorites=(SELECT COUNT(*) FROM user_favorites WHERE image_id=?) WHERE id=?",
+			array($image_id, $image_id));
+	}
+	
+	private function list_persons_who_have_favorited($image) {
+		global $database;
+
+		$result = $database->execute(
+				"SELECT name FROM users WHERE id IN (SELECT user_id FROM user_favorites WHERE image_id = ?) ORDER BY name",
+				array($image->id));
+				
+		return $result->GetArray();
+	}
+}
+add_event_listener(new Favorites());
+?>
diff --git a/contrib/favorites/theme.php b/contrib/favorites/theme.php
new file mode 100644
index 00000000..6324a268
--- /dev/null
+++ b/contrib/favorites/theme.php
@@ -0,0 +1,71 @@
+<?php
+
+class FavoritesTheme extends Themelet {
+	public function get_voter_html($image, $is_favorited) {
+		$i_image_id = int_escape($image->id);
+		$i_favorites = int_escape($image->favorites);
+		
+		global $user;
+		$username = $user->name;
+		
+		$html = "
+			Favorites: $i_favorites
+			<br>
+			<br>";
+			
+			if (!$is_favorited)
+			{
+				$html .= "<p><form action='".make_link("change_favorite")."' method='POST'>
+			<input type='hidden' name='image_id' value='$i_image_id'>
+			<input type='hidden' name='favorite_action' value='set'>
+			<input type='submit' value='Favorite'>
+			</form></p>";
+			}
+			else
+			{			
+				$html .= "<p><form action='".make_link("change_favorite")."' method='POST'>
+			<input type='hidden' name='image_id' value='$i_image_id'>
+			<input type='hidden' name='favorite_action' value='unset'>
+			<input type='submit' value='Un-Favorite'>
+			</form></p>";
+			}
+			
+			$pos = strpos($username, ' ');
+			if ($pos === false) {
+				$html .= "<br><a href='".make_link("post/list/favorited_by=$username/1")."'>Show my favorites</a><br><br>";
+			} else {
+				$userid = $user->id;
+				$html .= "<br><a href='".make_link("post/list/favorited_by_userno=$userid/1")."'>Show my favorites</a><br><br>";
+			}
+		return $html;
+	}
+	
+	public function show_anonymous_html($image) {
+		$i_image_id = int_escape($image->id);
+		$i_favorites = int_escape($image->favorites);
+		
+		$html = "
+			Favorites: $i_favorites
+			<br><br>";
+		return $html;
+	}
+	
+	public function show_favorite_marks($username_array) {
+		$html = '';
+	
+		foreach ($username_array as $row) {
+			$username = $row['name'];
+			$html .= "<a href='".make_link("user/$username")."'>$username</a><br>";
+		}
+		
+		if ($html == '') {
+			$html = 'Not favorited yet';
+		}
+		
+		return $html;
+
+	}
+	
+}
+
+?>