Thanks a lot. I think ive confused everyone here by asking about 2 different menus. Pauls menu seems to work great when you want your different categories to be in the menu, rather than just the 'category' link.

The other menu I was asking about needs to extend like a flyout, and then stay in place when you were on the products page. (http://www.jameschetwood.com/menu/menuiwant.jpg)
Ive managed to achieve this with a very dirty hack of the categories box. Id be happy to write some instructions but like I said, this is a very clumsy solution.