I found this thanks to [Mark Frauenfelder] on BoingBoing. The ‘Waterhobo‘ is a computer controlled sprinkler that fires upon anyone who’s cutting across the owners lawn. The video is pretty amusing. An infrared camera is mounted up top, and the computer measures motion in the image to determine if it should start firing.
I think it’d be more fun if the computer had to actuate a joystick, but [ashish]s visual based computer pong player is still pretty sweet. He’s capturing the game state with his webcam, and the computer processes the image and controls the pong paddle via tcp client connection based only on what it sees.