The folks over at The Barbarian Group created a rad iTunes visual plugin. Check it out.
“Here is this thing that does stuff in iTunes. There is magnetism, there is gravity, but on top of all of that, there is awesomeness. Watch as all the dots and ribbons go bouncy bouncy when you play music and trigger this mo-fo of a visualizer. This is the future of visuals. God help you if you smoke the reefer cause you can kiss your productivity goodbye.
By the way, don’t go crazy with the A and S keys - they add or subtract a hundred particles at a time - tap once or twice and wait for the results. If it starts acting poorly because you hit a bunch of keys, just quit and restart.”