a) a FM receiver uses a (microscopic) fraction of power compared to Pandora over 3G which is almost a full-throttle thing. Oh, and it's $free$. b) It has an FM transmitter. This way you can listen to it in a car without additional adapters. My car has no fancy-shmancy ipod dock or bluetooth option, so I certainly appreciate this c) if you have a transmitter, a receiver is a no-brainer. d) it might be part of a bundle (like the FM radio came in a bundle with the bluetooth chip in the N800). So, if it's there anyway, why not use it.