According to a comment in a post at Engadget it appears there may be a way to get the Belkin Auto Kit to work with the iPhone. I haven't been so fortunate. It appears (as the article suggests) to charge but it steadfastly refuses to play audio through the dock connector.
On the other hand having lived through Treo smart phones it is great to have a device that handles connecting and transferring Bluetooth calls as well as this does. Talk in the phone and press the button on the headset and the call is transfered seamlessly. A thing of beauty.