Here’s a YouTube showing how to control the NXT using the gravity sensor of a Apple MacBook Pro in order to remote control a LEGO MINDSTORMS NXT robot. They connect via bluetooth, and the Interactive Geometry Software Cinderella.2 is used as controlling software. It reads the data from the gravity sensor of the MacBook, processes it and then controls the motors of the NXT robot accordingly.

More info about Cinderella at http://cinderella.de