Good old Johnny Chung:

http://www.cs.cmu.edu/~johnny/projects/wii/

Check out his other stuff on projection too!

What about this idea?

http://www.youtube.com/watch?v=8-AJnLMzE0k&NR=1

Has anybody tried this? I was very interested so i bought the bluetooth dongle and then found out later that only certain kinds work with the wii-mote.

I've tried it. I bought a cheap (like $20) HP dongle from wal-mart. It took ALOT of messing around with, and installed about a dozen BlueTooth drivers. I made the IR glasses and everything (for the head tracking). It worked alright, but wasnt too impressed. Watching Johnny's video about head tracking made it look alot cooler than it turned out. The sample program he uses needs some refining, but I dont have the time to do it.

As far as everything else, once I was able to connect to the PC with the wii-mote, I found its better suited as an input device than a tracker. Use GlovePIE, and the world is your oyster. You have control over just about every feature of the wii mote. The accelerometers, rumble, speaker, buttons, IR, etc. (dont think you can access the on board ram yet). You can even put use to the nun-chucks and the Fit board! Look around, someone made a remote-controlled car using all the Wii inputs accessories.

http://carl.kenner.googlepages.com/glovepie_download

That's the GlovePIE homepage. No updates for a year now. Obviously still a very popular download, though - I could only get one to work, and I've snagged a copy of 0.29 just in case it vanishes before I manage to locate my bluetooth dongle.