Its a system where you fully interact with a screen, using gestures (even body movements) to control a computer that then shows the result on the screen. It really can't be described properly, but I suggest you take a look at the video which is online here; http://multi-touchscreen.com/perceptive-pixel-jeff-han.html
The best thing about it is that the whole system was put together by a boffin and "about a ton" of hardware in his bedroom. Anything is possible!
Space Invasion. I found this rather unique key in my old house. I've always wondered if it was brought to earth by an alien race invading our planet. Maybe.....
