Wii: Unbelievable

Head Tracking for Desktop VR Displays using the Wii Remote

Using the infrared camera in the Wii remote and a head mounted sensor bar (two IR LEDs), you can accurately track the location of your head and render view dependent images on the screen. This effectively transforms your display into a portal to a virtual environment. The display properly reacts to head and body movement as if it were a real window creating a realistic illusion of depth and space.

A couple of more projects are at Johnny Chung Lee‘s website.