Globes, CNET, TI: TI and XTR 3D demo gesture recognition technology at the 2010 Mobile World Congress in Barcelona these days. The demo appears at Youtube too:
XTR claims its technology uses "a single standard webcam". However, the XTR device in the demo does not look like the standard webcam. My sources told that the trick is in so called "split lens" - I would love to learn more about this approach.