I ordered an "iTrip Auto" as soon as I bought my Touch last month. It's basically a cable with a cigarette lighter plug on one end, the Dock connector on the other end and the FM transmitter in the middle. The upshot is that you can listen to your iPod in the car over FM without draining the battery.I just have the griffin itrip, and it works great.
IMHO the iTrip Universal is much better then the iTrip or iTrip Auto. I just bought it today and it is as good or better then the original one I got years ago. I still need to figure out how to convert it to international mode so I can use 87.9 as my frequency. I highly recomend the universal.I loved the original iTrip that plugged into the headphone jack. I have one on my iPod 4G. I have two of the newer iTrips that work with the Dock connector. I would not buy them again. They interfere with cases and covers. The line out through the Dock connector is too weak. It's not loud enough. I will be purchasing a new iTrip universal that works through the head phone jack soon. If you do buy the Dock connector version, it works better in international mode and with sound check on the iPod turned off.