Touch Sensor, Line Following, and propellor bots. He programmed his bot to follow the line but the weight and placement of the RCX made it fall apart when he put it on the mat.
Webpages and pictures on http://www.marshall.edu/LEGO Web camera on http://legocamera.marshall.edu NASA site of Remote Sensing on http://SENSORSCITY.marshall.edu Teleoperate Mars and LEGO CITY at http://lego.marshall.edu