I would recommend something simple to start. How about this USB nerf rocket launcher from ThinkGeek: http://www.thinkgeek.com/geektoys/warfare/8a0f/ http://www.

I would recommend something simple to start. How about this USB nerf rocket launcher from ThinkGeek: http://www.thinkgeek.com/geektoys/warfare/8a0f/ http://www.thinkgeek.com/geektoys/warfare/8a0f/ It's cheap ($25), cool, has horizontal and vertical movement plus firing, and the software is Windows-only. Not to mention that a Kinect + rocket launcher combo would be awesome. My secondary vote (and it's a selfish one) is this pedometer that only has Windows software: http://www.mattcutts.com/blog/my-favorite-pedometer-omron-hj-720itc/ http://www.mattcutts.com/blog/my-favorite-pedometer-omron-hj... . Another possibility would the the Fitbit. I'd be happy to get you any of these devices if you wanted to document what you find with adafruit-like clarity. Even better would be an exchange to hook willing USB reverse engineers up with people willing to provide devices for those engineers. :)