I'd love an update on this, and have you ever thought of implementing the 'vision' system w/ a kinect?
The Kinect is fragile, takes about an amp of current during operation, and requires a processing capability beyond the Arduino.
Just a thought.
I knew a kinect would have to attach to a mini-itx or raspberry-pi or something beefier than an arduino, but I didn't know it suched _so_ much power or was considered fragile, thanks for the heads up!
I'd been considering looking into them for a UGV I'm brainstorming over, but perhaps not anymore!
Parallax is using the Kinect on their EDDIE robot chassis which uses a laptop or a mini-itx to process the Kinect video data stream. The tilt motor in the Kinect is not very robust and can overheat quickly when continuous tilt commands are sent to the Kinect. Check out this link: http://www.norrislabs.com/