Someone made a Rubik's cube solver using the Lego NXT set:
[youtube]5fAn5A0HbhU[/youtube]
http://tiltedtwister.comMaybe not as impressive as some of the other solvers out there,
but still amazing considering only basic NXT parts and sensors
were used. (The colors on the cube had to be modified because
of the limitations of the basic light sensor.)