MacBook Pro and PowerBook owners can use a new iTunes plug-in which makes the illuminated keyboard on their laptops flash in time to the beat of the music played.
The software is called iSpazz, and is being made available as donation-ware. The developer expressly states that the software is being made available without any warranty or support of any kind.
"Oh, and before I forget: no warranty whatsoever. If the display flicker mode eventually kills your computer"s backlight, it"s not my problem - sorry," the developer states. Neither keyboard nor display have been built to flash intensively in this way."