Mobot is my first attempt of a walker , it has 4 legs with 2 degrees of freedom . By now I can't give any more info because mobot is so far just a base and I have not implemented any electronics , but the brain will most probably be a basic stamp II with a servo controller and Ir proximity detectors as a start . It uses HS 303 servos and has untill this date cost me about 150 $ . For more info , comments or suggestions mail me at christian.vlaskowits@descom.se