We'd initially intended to do all the autopilot functions in Lego, but the gyro programming turned out to be beyond our abilities. So we switched to a commercial stabilization unit to keep the plane level and just use the Lego Mindstorms for waypoint navigation. In the next few months we'll integrate a Bluetooth GPS module, but for now we're just using a HiTechnics compass sensor for basic navigation. The mechanical components are the same as they will be for the GPS (ailerons and elevator for flight stabilization, rudder for navigation), so the below looks and works very much like the final version.
Excuse me while I b0w.