If you're tired of buying FM transmitters that cut in and out and deliver horrible sound quality, Sonnet offers you a product that might be of interest: a battery-free FM transmitter that--gasp--works!
Finally, an FM transmitter that really delivers--the Sonnet PodFreq Premium FM transmitter amazed us in testing by delivering a clear, strong signal with a great range to our stereo. If you've wasted money on other transmitters that have that have a range of inches, then this is the product for you. The iPod fits snuggly inside the PodFreq, which can transmit to any FM setting from 88.3 to 107.7. The PodFreq doesn't use batteries; instead, it draws power from the iPod itself (a factor to consider). It has FireWire and mini-USB ports to make up for the covered connection port, and it comes with a soft carrying bag.