GPS-enabled iPod with motion-dependent track selection

Similar to [hippo]'s idea of a 'GPS-enabled iPod with location-dependent track selection', except that the unit would understand several types of motion and associate this motion with various tracks or Genres. Configuration would have to be done from some desktop app where songs could be associated with various motion types, but a wide variety of motions could be understood by a GPS, such as: jogging, walking, driving in town, driving on a highway, etc. The basic selection criteria would be based on ranges of speeds, but other criteria could be applied in a more advanced unit, such as if you are going certain speeds in certain locations (4-8mph on a street might be 'jogging', while the same speed on a body of water might be 'sailing'). You could, for example, have music that matched your current driving style; if you are cruising leisurely along a windy country road, it could play a peaceful Bach piece, if you are speeding at 80mph in a busy metro bypass, some Juno Reactor - Mona Lisa Overdrive.