How to make a mobile robot with only one motor (servo)?

http://www.surveyor.com/?gclid=CNHhqNbmlYwCFRRrUAodPSrrew

http://www.shopping.com/xGS-How_To_Make_Robot~NS-1~linkin_id-8008897

http://www.hobbytron.com/RobotKits.html

http://www.robot.org.uk/htm_docs/robot_kits.htm

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/484/3534/00126046.pdf

http://www.kipr.org/boards/viewtopic.php?t=45

http://www.societyofrobots.com/robot_arm_tutorial.shtml

http://www.elexp.com/newsletter/news0606.htm

http://www.cs.cmu.edu/~chuck/robotpg/robo_rsrc.html