This is my new tool for browsing categories, far from finished. Works only in FireFox, and probably Mozilla. To try it out, copy the following lines into your monobook.js page:
// [[User:Zocky/CategoryBrowser.js]] - please include this line
document.write('<script type="text/javascript" src="'
+ 'http://en.wikipedia.org/w/index.php?title=User:Zocky/CategoryBrowser.js'
+ '&action=raw&ctype=text/javascript&dontcountme=s"></script>');
Clear your browser's cache and when you click a category linke, the category browser should appear. To get rid of it once it is displayed, go back a page in your browser.
