Well, I did a lot of research into this predicament. I looked at the Jabra Cruiser and the Motorola T505. I known it dies t charge the iPhone but if you want a good speakerphone/ transmitter you have to make sacrifices for now. The Jabra is nice but I noticed the FM transmitter is a bit weak. I love the T505 it has a really strong transmitter and works well with the iPhone 4. The only drawback I think is that it is a bit more involved with the setup.
There is supposed to be a new Motorola coming out soon called the motorola Rocker. Should be way better than the T505. Look out for that! Good luck on your search!
