My IBM Thinkpad has a sensor that measures accelleration and the attitude of the computer. The purpose is to detect a fall and retract the head on the hard drive to prevent a head crash.
Apple just added this capability to its latest line of laptops. Clever folks have discovered how to access the sensor in software. So it had to happen: turn your Macbook into a light saber.
I'm betting that someone will accidentally test that head parking function while showing this trick off. I hope the saber software shares the sensor.