I was working on a project earlier where I was using the wp_nav_menu function in WordPress to create a menu. By default, WordPress creates menus which are wrapped in layers (<div>), an unordered list (<ul>), list items (<li>) and then a link (<a>). However, on this project I wanted to use jQuery UI to generate a navigation, and that required just links (<a> <a> <a>).
So, to strip out all of those extra HTML tags, I used the following javascipt (as I was already relying on jQuery and javascript anyway).
var newmenu = '';
jQuery("#nav ul li").each(function() {
newmenu += jQuery(this).html();
});
jQuery("#nav").html(newmenu);
This works by firstly looping through all of the list items in my navigation layer, and copying their contents (the menu link) into a variable. Then, I replace all of the HTML contained within my navigation layer with that string. Easy!