I don't think this has been mentioned before.
As you may know, some players have a built-in FM tuner. I think it would be a neat idea to write a library that allows the computer to use the tuner to listen to radio. I know that the current builds or Rockbox can use the player as a HID device, i.e. move the mouse, control PowerPoint, etc., and I figure that the tuner could be used in the same fashion.