Hello!
Okay, so I was messing around on my phone in the car yesterday. I've tried to hook my other smart phones into my , FM transmitter to listen to music, to no avail.
I decided I would attempt it with the droid. It worked just fine. The analog jack fits the size of the FM transmitter. What's even better is when you get a call, it will pause the music you are playing and the call will generate through your car speakers.
Now this part is untested so far, but because the new power cords from Verizon work as the home charger and the USB cord, with the there is a place on the top of the plug that will allow you to plug in your USB device to charge while you are plugged into the transmitter. A work around to purchasing a car charger? Maybe, but The Droid will charge off the computer when plugged in that way. I'll have to try it and get back.
EDIT: It does charge