Seems like a Wii Nunchuck will make a great input device for the project. I'm deeply indebted to folks who have put up such great tutorials on how to do this, Tod E. Kurt in particular.
For anyone interested in using the nunchuck with Arduino, there's a nice adapter piece that allows for a much nicer interface with the nunchuck:
Not knowing about the adapter, I cut the cable to get at the cords. It's not pretty (below). Hopefully I'll find a more elegant way to deal with this kind of wire..
p.s. Here's a vid showing the potential of the nunchuck..
Hurray! I can’t believe how far this idea has come! I’m very excited to see it!