Other option, you run the itunes visualisations full screen, loose built in ituens controls, use somthing else to control ituens. salling clicker lets you control itunes through a bluetooth mobel phone, sony erriconons work the best, or a symbian based smart phone (nokia series 60, sony erricons p800,p900,p910). That way you can control it from the dance floor if you feel the need. Or you coulde run some sort of remote software for itunes to control it while its in full screen mode on the other screen.
I break stuff.