Pong Head is my take on the game Pong, where users control the paddles with their bodies, and the loser's head becomes the ball.
It uses a Microsoft Kinect, Openframeworks, and OpenNi to track the users. The code for the game itself is super simple, with no win conditions, and the ball speed starts fairly slow (though it gets pretty dang fast).
Originally this was a project for For Dano's Computational Cameras class, but I'm planning to recreate it in the browser using javascript. In the meantime, you can download the source code on github.