I use a cig lighter adapter with a retractable cord. Here is an example from Amazon. I'm not necessarily recommending this one, but just as an example.
Just search for retractable cig lighter adapter for Droid on Google and you'll get lots of hits. There are so many that I don't even remember which one is mine. It has so far worked flawlessly for the past 6 months.
Some blackberry cords are the same as the droids cord I have a straight one that is like 2 feet long to use in my car. Coupled with an old ipod car charger that is essentially a universal usb charger
