FM transmitters are the easiest way to connect an iPod to your car stereo - especially if you don't have an aux in or tape player like me. I've tried a few different models including the iTrip and the Monster iCarPlay; they work but the sound quality is sometimes "eh" and suffers from interference. I recently picked up a Kensington Digital FM Transmitter and it is a huge improvement. Almost no interference and the audio is loud and clear. It will tune to nearly any FM channel (
although not 87.9, which is clear throughout most of the US) and is very easy to use with a bright, backlit LCD display indicating the frequency and 3 programmable presets.
Update: To tune to 87.9, hold down the two rightmost preset buttons. The tuning will then scroll past 107.9 and start over at 87.5, allowing you to tune to 87.9. I have no idea why this is "hidden" but it works. Sadly, it resets to 107.9 when you turn off the car, and you can't set a preset for 87.9, but it does work and the sound quality is awesome for an FM transmitter.