I would recommend checking out these videos, this guy has managed to recreate Sony's Motion Controller using a wiimote, a wiimotion plus, a ir led, and a playstation eye. It's still in early stages but it's cool to see what he managed to do.
http://www.youtube.com/watch?v=Kv29VUZAuyc
http://www.youtube.com/watch?v=6essv72LqSU
UPDATE: Apperently this guy isn't the first one to do this. This doesn't surprize me as I have thoguht of doing it before but my lack of knowledge on Wiimote to PC connection has stopped me. What's more impressive is how it is pulled off in this video here http://www.youtube.com/watch?v=WWUBKa7fGcY...feature=related
http://www.youtube.com/watch?v=Kv29VUZAuyc
http://www.youtube.com/watch?v=6essv72LqSU
UPDATE: Apperently this guy isn't the first one to do this. This doesn't surprize me as I have thoguht of doing it before but my lack of knowledge on Wiimote to PC connection has stopped me. What's more impressive is how it is pulled off in this video here http://www.youtube.com/watch?v=WWUBKa7fGcY...feature=related