opensocial_timestamp_of_last_visit.xml

<?xml version="1.0" encoding="UTF-8"?>
<Module>
  <ModulePrefs title="Timestamp of last visit">
    <Require feature="setprefs" />
  </ModulePrefs>
  <Content type="html"><![CDATA[
    <script>
      var prefs = new gadgets.Prefs();
      document.write("Timestamp of last visit: " + prefs.getInt("timestamp_canvas"));
      prefs.set("timestamp_canvas", new Date().getTime());
    </script>
  ]]></Content>
</Module>