The Green Machine is a LEGO drag racer. It has and average speed of 4 feet-per-second. It uses a PID algorithm and the MindSensors NXTLineLeader to stay on the line.
Robot Drag Racing - Ultimate speed and accuragy test!
Past and preset rulesets:
Juggernaut is a LEGO sumo robot. It is controlled by the LEGO MindStorms RCX, and programmed in RobotC. You can see it compete, as well as some other bots, at the BrickWorld 2012 sumo competition video here: http://www.youtube.com/watch?v=Iq7nSlZqF8w It placed fourth.
Wheeled Envoy Doggedly Gyrates Ecstatically (or, W.E.D.G.E.) is a LEGO sumo robot. It has advanced programming, and perhaps the best possible wedge you can make with LEGO. It placed 2nd at the BrickWorld Chicago 2012 Super Sized Sumo Event. Programmed with RobotC 3.x. You can see it, as well as other entries in the BrickWorld contest here: http://www.youtube.com/watch?v=Iq7nSlZqF8w