My company, Toolfarm, sells Trapcode plug-ins, which are awesome video plug-ins for Adobe After Effects, Final Cut Pro, Avid and other hosts. Peder Norrby, the man behind Trapcode has just released a free visualizer for iTunes.
Download the AlphaOmega visualizer for iTunes
On a technical note, I noticed it doesn't work in Full Screen mode. I'm going to email Peder and tell him. Maybe it's just my OS. Anyway, it's cool and it's free, so go download it!