The Perturbed Desktop
If you've invested in one of the latest apple powerbooks, you have to download this orientation visualizer that exploits the built in 'Sudden Motion Sensor' intended to prevent data loss by locking the hard drive if you accidently bump or drop the machine. The "perturbed desktop" doesn't really have any purpose but I bet steve wishes he thought of first as this offers a new input method for user interfaces to control games, phones, PDAs and other mobile devices.
download here