iSpazz is a iTunes plugin for OS X, which makes your MacBook Pro/PowerBook backlight keyboard into disco light array; flickering and blinking with the music.

Using it is simple, just download the plugin, uncompress and copy it into the iTunes Plug-ins folder. We aren't sure if using this software for prolonged periods can kill your backlight forever, so use at your own discretion and risk. But it could be good fun to show this off on your MacBook Pro/PowerBook once in a while. Grab it from here.