Painting The Mona Lisa with MS Paint (the stock paint program for Windows).
From the author:
Using infrared (IR) light pens and the Wii Remote, it is possible to create very low-cost multi-point interactive whiteboards and multi-point tablet displays. Johnny Chung Lee, Carnegie Mellon University. The software can be downloaded at http://johnnylee.net
Don’t get left behind, learn how to show your affection for your fellow man.
Christmas Light Hack, powered by your stereo.
http://www.metacafe.com/watch/964369/christmas_light_hack_powered_by_your_stereo/
If you watch poker on TV, you will see players shuffling their chips while deciding their bets. This shows you how to do it.
Any contraption that involves duct tape is worthy of a clip, and some music!