Off the top of my head, and using joomla 1.5
Go to module manager and make a copy of say, Main Menu
Assign that module copy to a unused position like menu_dropdown
Assign that module copy to appear in all pages
Create a new article which only content is {load_position menu_dropdown}
You should have enabled the Content - Load Module
plugin
Now find the article url, example index.php?option=com_content&view=article&id=57&Itemid=26
and add &tmpl=component
at the end.
So that url looks like index.php?option=com_content&view=article&id=57&Itemid=26&tmpl=component
this url should be the first parameter to jkpanel.init
NOTE
You should be careful that the article doesn't show up normally, maybe by archiving it.