What they came up with is a kind of self-contained module that you add onto your Xbox 360. It has a video camera in it that tracks where your body is and what you're doing with it. It also has a monochrome camera (it works with infrared) that reads depth — how far away your body and its component parts are — and a highly specialized microphone that can pick up voice commands. Along with all this hardware, it's got a ton of software that tells the Xbox how to find your body's various joints (it tracks 48 of them), how to keep track of multiple players at the same time, how to tell your Hawaiian shirt apart from the colorful wallpaper behind you, and so on. Microsoft even did an acoustic study of living rooms, so Project Natal can tell when you're talking, when your buddies are talking and when somebody in the game is talking, so it knows whom to take voice commands from.

Kipman also showed me a version of Burnout that had been set up to work with Project Natal. Burnout is a serious game, not just a tech demo — it's a polished, fast-paced racing game with high-end graphics, and I happen to have played a lot of it. With Project Natal, instead of using a joystick, you steer by holding your hands up in the air like you're gripping a steering wheel. To hit the gas, you move your foot forward along the floor. To brake, you move it back. [What? NT by laudablepuss --Fussbett] To trigger the turbo boost, you do a gear-shifting, fist-pumping movement with your right arm. Awesome.

It takes a few minutes to get the hang of it. You tend to oversteer, since you can't quite believe this thing is going to pick up your movements, so you exaggerate them. But soon you start to trust it, because it does actually work. I couldn't detect any significant latency. And there's definitely an extra edge to playing a game with nothing between you and the screen but your clenched, white-knuckled fists. I'm a hard-core gamer, so I'm not the person Project Natal is targeting. I love my controller as it is. But the appeal of Project Natal is real. You could compare it to the difference between regular movies and 3-D movies: it puts you in the action in a way that nothing else could."