Mp3 player with GPS
According to BBC, the researchers finded an original method to use the GPS receivers with mp3 players. The owner of this mp3 player can setup the coordinates to the place where he wants to arrive and in time the system will guide him using the volume in headphones.
The right headphone will be louder when he must go to right, and the left headphone will be louder when he must go to left. the volume will be normal when he must go forward.
I think that in future the user will be able to personalize the sound alerts in cases like that when the owner is in some unknown area and wants to go to a bar, musem or restaurant.