Check out this cool Rubiks Cube solving Lego NXT Robot.
“Tilted Twister solves Rubiks cube fully automatically. Just place the scrambled cube on Tilted Twisters turntable. An ultrasonic sensor detects its presence and starts to read the colors of the cube faces using a light sensor. The robot turns and tilts the cube in order to read all the faces of the cube. It then calculates a solution and executes the moves by turning, tilting and twisting the cube.”
Here’s a video of it in action.