Check out the new iPhone and iPod cradle at PerformancePlusiPod.com
This cradle works with factory USB connections, Alpine, Kenwood, Sony, and Pioneer radios. It works with all iPod and iPhone car kits with the 30 pin connector.
I have this one connected to an iPhone and iPod classic with an Alpine iDA-X100 through the Apple universal A/V cable. It even streams video from my iPhone with the AirVideoFree app.

It makes the maps function with the iPhone 3Gs work like a real navigation.
Get it at PerformancePlusiPod.com or HondaiPod.com.