Using the CBL 2 digital breadboard cable and a Raspberry Pi, I am going to try to make an autonomous robot. It will be more of a proof-of-concept build as the Pi can perform all the features on its own, but why not? The CBL 2 will interface the calculator to the Pi through the digital output port (see page 17 of the CBL 2 Technical Reference Guide) and provide the sensor interface. I'll be sensing walls with an LED and an appropriate filter over the TI Light Sensor (which has a very wide spectrum response which includes much of near-infrared). The brightness received would indicate a wall's presence, but it'll have to be much brighter than the environment. I have some motor controllers lying around somewhere; otherwise I can get access to some through my robotics class.