If you've seen the movie Minority Report you probably remember the impressing gesture based computer interface that Tom Cruise uses there. Well, my latest experiment is far from the sophistication of that tool, but for it being made with Flash it's quite nice and entertaining:

Minority Cube allows you to control the rotation of a cube on the screen by simply moving your hand in front of your webcam. (I just hope that it works with every other camera model as well as it does on my machine.)