Back in November, I picked up a Kensington Digital FM Transmitter for my iPod Classic. And on my way back from Dustin and Sarah's wedding yesterday (congratulations, you guys!), it occurred to me that I hadn't yet posted a review of the device.
Having never used an FM transmitter before, I was unsure about the reception quality. Thankfully, this specific Kensington model is top notch. It's rare that I encounter static, and I've noted that it most often happens when driving under a particularly large overpass. The audio quality is excellent, though I find that I have to turn up the volume on my car stereo a little higher than I normally would with the corresponding audio CD. This might simply be related to the compression that MP3's provide, but it's a minor nuisance.
The unit provides 3 preset buttons, which is very useful to lock in multiple unused stations. This feature was really handy when I went to the mountains last Thanksgiving; one of the preset stations I was using in the RTP area was being used in the Asheville area, and switching was simply a matter of pressing a button (and then tuning to the right place on the receiver).
While your iPod is attached, the unit charges the battery. Unfortunately, there's no option to not charge the battery, which would be useful for battery conditioning purposes. I don't use this unit every day, so this minor problem doesn't impact me as much. One other minor annoyance is that the iPod-style connector doesn't lock into place. This makes it much easier for the cable to fall out, though I have only seen this happen a time or two.
Overall, I really like this unit. According to the Amazon product page, this particular model is being phased out and replaced by the Kensington LiquidFM Transmitter, which has much lower reviews. If you want one of these models, I suggest picking it up ASAP. You will not be disappointed.