Last month, I saw Johnny Chung Lee’s video that showed how to detect finger movement using a Wii remote. He summed it up best at the end of the video when he said it was cool, but he couldn’t really think of something useful to do with it.
Now he has a video that shows how to make a multi-touch interactive whiteboard using the same Wii remote.
http://www.cs.cmu.edu/~johnny/projects/wii/
This could be very useful in the classroom. I own a Wii with two controllers and over break I plan to try this one out. I need to pick up the Bluetooth adapter.