This robot-car made with the new LEGO Mindstorms NXT Robotics Invention System automatically parks itself if it detects enough space between two objects. It has an ultrasonic sensor that detects the length of free spaces. Then, when it detects enough space, it makes the necessary movments to park. And when you say "GO!" it returns to the road.
LEGO Mindstorms was named Consumer Electronics Show Editor's Choice by Popular Mechanics magazine and now comes with a 32-bit processor, redesigned sensors, Bluetooth and more.