Toss your TV REMOTE just gesture.

“It’s a technology that we call Natal. It’s a little camera and microphone that sits on top of your TV set. And if you want to control the TV, you don’t go get some remote control or big fat gaming thing. If you want to look through TV channels, you just gesture, and the computer recognizes your voice, it recognizes your gestures. You want to see the next sports program, you go like this, it will cycle you through. You want to play a game and you need to jump, you jump. I’m not going to jump too hard; a little bit too high altitude here in Bogota for that, at least for me. But it recognizes you, it knows your voice, who you are, your gestures, what you’re doing.

“And if you think about that in a lot of settings, why am I carrying this thing? I’ve already forgotten three times where I set it down. I should just be able to go like this, and the camera should recognize that gesture and control the slides for me, and let these kinds of things freely happen.”

Source:  Ballmer on Natal: 'The most exciting product we'll bring to market this year'