As you might already know from my “Making The Game” category I’m currently writing my Master’s thesis on natural user interfaces (NUI).
This research area also includes the computer control via body movements and gestures, as they are already on the EyeToy or the Kinect.
Besides the mere paperwork I also develop a NUI program that is easy to operate without input devices like mouse and keyboard. So i played a little with the webcam framework in flash and programmed a small motion detection game I don’t want to hide from you.
The aim of the game to catch the falling diamonds with the hand in front of the camera.
You should step two steps away from your webcam to have more space to move in front of the cam.
Once four diamonds slip through, the game is over.
Motion Control via Webcam
Click to play in a larger window.
or post your Highscore on Facebook: 
Of course I would love some feedback,
Max