I'd not come across this guy before, many other people probably have though.
Johnny Lee of the Carnegie Mellon University has adopted the Wii-mote as his IR sensor, and using a bluetooth connection to a PC has created Whiteboards, and Head Tracking.. amongst other uses.
I've just had a browse of Johnny's sourceforge page, and although the code has been ported to Mac (albeit with a few bugs) he's still looking for a Linux Developer to port the application. I might have an 'unofficial' play with the software to see if I can port it - but I'm in no way an experienced programmer. If you can do it - please do take a look.
I'm sure other people can see the potential that this could have on Linux games :)
We'll have 3D shoot-em-ups first.. come on :)
Here's the video that impressed me the most: