Johnny Chung Lee has been doing some pretty brilliant stuff with the Wiimote. He has been using the Managed Library for the Nintendo Wiimote to create C# applications that use the Wiimote in different ways.
Most games and applications we see using the Wiimote have the user move around the controler to manipulate what they see in the display. Johnny Lee has changed that, making the user move the sensor around instead. This lets him put together some neat input controllers, like finger tracking applications, multi-point interactive whiteboards, and 3D virtual-reality displays.
I highly recommend you check out some of the videos he has put together, particularly the one on head tracking. Great job, Johnny! Looking forward to your next video. Applying these in software applications could really open up the doors to how we interact with our technology.