Check this out!
If you look at the source of that page, you will see that there is a script “
/j/jsloader.js” loaded at the head of the page, and the only indication of where to apply the script is done by giving the navigation’s wrapping element a class of “
magicmenuleft“. The script searches for that, then applies certain functions to elements containing that class.
The method used by Ben Nolan is similar, but even less intrusive. We both use CSS selectors, but his is possibly more efficient, bandwidth-wise.