MIT Handyboard is a much more powerful platform for hobbyist robotics. Check out the light seeking robot I built:

http://www.youtube.com/watch?v=KaeWc4RPhok

I'm unclear as to what exactly the robot is doing. what does it do with sensor data? does it test possible paths to a certain point and then backtrack or is it naive hill climbing? something else?

Neat! Reminds me of the 'elektor' turtle from the 80's, did much the same thing with a bunch of opamps.

It also was clever enough to find a place to recharge iirc.

There was another one in one of the early 'byte' issues.

Given that Roombas are programmed in Lisp, how long before someone ports the Roomba AI to Lego?