You've probably all heard of the Kinect and the fact that it only took about three hours after release before someone got it running on Linux. A lot more has been done in the mean time, and creativeapplications.net has a nice writeup of it.
And, of course, there is also Johnny Chung Lee who has been working on Kinect. If you have seen any footage of a Wiimote being used for a cheap multi-touch screen, that was probably Johnny. He's even featured on TED.
Update: There is some more fun stuff over at Ars Technica.