public static function plugin($pwd = null) {
		if (empty($pwd)) {
			$pwd = self::path();
		}

		$plugins = CakePlugin::loaded();
		if (array_keys(self::$_plugins) != $plugins) {
			self::$_plugins = array();
			foreach ($plugins as $plugin) {
				self::$_plugins[$plugin] = CakePlugin::path($plugin);
			}
		}

		foreach (self::$_plugins as $plugin => $path) {
			if (false !== strpos($pwd, $path)) {
				return $plugin;
			}
		}

		return false;
	}