Suffering from iPod withdrawal while driving in your car? iTrip, an FM transmitter produced by Griffin Technology, plugs into your iPod's (regardless of its generation or model type except the original and the iTrip Black.
Though the sound quality through any portable FM transmitter is less than perfect, the iTrip actually sounds decent. Sometimes some interference does occur. You can choose the broadcasting frequency from the iPod's interface that suits you. While the iTrip doesn't add much weight to the overall iPod setup, it seems to drain the battery much faster since it doesn't run on its own power source, such as batteries.
There is a new iTrip model available for the fifth generation iPod (iPod video). It connects to the bottom of the iPod instead of the top and has a digital display. It is available in both black and white.