The Load XML extension allows you to use an external XML document as your menu data source.
It works using XMLHttpRequest
(aka AJAX)
to load the XML,
then imports data from that to populate the menus on the main page.
This is only possible because
of a menu method called
um.refresh, which re-initialises the navigation tree as though
the page had been reloaded.
This extension is not supported in Mac/IE5, Konqueror 3.2, Safari 1.1 or earlier, Opera 7.5 or earlier, or Mozilla builds older than 0.9.4 (Netscape 6.2).