today, a friend sent me to a link to see a guy having fun with wiimote
wow!
actually it is simple
the wii remote has a infrared detector and you use something that emits or reflects infrared light
the efects he’s doing with it are remarkable, take a look for yourself
and here’s the link to Johnny Chung Lee website
http://www.cs.cmu.edu/~johnny/projects/wii/