Just a snipptet of jQuery code for a project Will is working on, although we might be able to use this in Confluence as well to highlight links to the current page (ie. show which section of a site we're in)...
You'll obviously need jQuery to be present on the page...
jQuery(function($){
$('a[href]').each(function(i,a){
if (window.location.indexOf(a.href)!=-1) $(a).addClass('current-page');
});
});
I've not tested the code, it's off the top of my head and could contain bugs, but give it a try...