I actually came across these videos come time ago, I forgot why I had them rotting in WP’s drafts. So here they are.
First one’s about how Johnny Lee uses the Wiimote to do finger tracking. This enables him to do some neat stuff like manipulate things a la Minority Report.
I find the second video cooler. He uses the same concept, Wiimote tracking, to do head tracking. This allows him to create a virtual reality window on his monitor via off-center view frustum in a 3D world.
I believe he has some code on his website, do check it out.