the newest revision of apples powerbooks features an accelerometer, that detects if you drop the powerbook and parks the hard disc heads (a thing already found on older ibm-machines). now a guy figured out how to tap into the accelerometer and use it to display all kind of funky stuff (e.g. a window is fixed in space, while the powerbook rotates). this led another guy to program a python script whith which you can control itunes. just give your powerbook a mild slap on the head and it switches to the next song. i see some really funky stuff coming up for those powerbooks….
update: someone already did program a game for the tilt sensors. let the fun begin.