My biggest gripe since I had my first 600 is that the audio jack is on the bottom of the device; it's always made it difficult to use my Treo as an MP3 player in almost any situation. In my car, I have a windshield-mounted holder that is great for keeping the phone charged, but useless for doing so while I'm trying to play MP3s through the car stereo, when I have to usually lay the phone on the seat so I have access to the inconveniently-placed audio jack.

Reading the specs, it looks like the 680 may actually have stereo Bluetooth capabilities? If so, I'd like to find an adapter that I can stream audio to via Bluetooth, and which can either plug into the AUX jack of my car stereo, or broadcast FM to it. Anybody with experience or suggestions about where I can find a good adapter?