Video: Hacking a Wii Remote into a Multi-Touch System

I love TED videos; the WOW factor of many of these is off the charts.  How about taking a $40 Wii remote and creating the equivalent of a multi-thousand dollar whiteboard, a multi-touch interface, or even a head tracking system!  I am just floored by the innovation!
 

Video: Dean Kamen-Prosthetic Arm Prototype