I like HotKeyNet. It is more user-friendly than AHK and very well supported. It is also very functional. There is nothing I want to do that I can't do with HKN

Katharis has done some very cool stuff with running multiple windows on 1 PC (using HKN) He has arranged it so there is a 'hole' in his main's WoW window so that he can see the minimap of his slave and his main for gathering purposes.....VERY COOL. I am almost tempted to redesign my setup to try this!!

Might be worth you having a quick play with HKN.....it also has a very light footprint, and easy to install/uninstall.