Hi Nicolas -
I recall a similar discussion on this list before, but I can't seem to find it. The consensus seems to be (and I'm inclined to agree) that one of the best low-cost options is the iRobot Create, which costs about $130 USD. You can drop a netbook or laptop on top, and along with a Kinect, you have a very capable robot.

-Dan

2011/1/27 Nicolįs Alvarez Picco <nicolasapicco@hotmail.com>
Nicolas