Belkin makes a good model.
They target iPod users but it can work with any headphone jack. Works off of 2 aaa batteries.
Perfect for the commute. I've had to switch between 88.5 and 88.7 on some roads in town but overall it's static free. Works great in our house too... been able to get about 25 feet w/o distortion. 30ft. if you leave the unit alone. Just for kicks I had my wife follow me in her car in our neighborhood and she could tune into my broadcast. Now if there was a way to boost the power or plug it directly into the lighter...
Two tips, remember to turn it off when you're done. It doesn't have an auto-shut down feature. Also, keep your audio on the Axim unit at half volume otherwise you'll muddy up the audio. Use the car stereo to control main audio volume
I purchased mine at circuit city.
TuneCast Mobile FM Transmitter.
http://catalog.belkin.com/IWCatProdu...duct_Id=140984