If you prefer more than listening to just song from iTunes on your iPhone then this device could work for you. It is called the XM SkyDock and what this gadget does is allow you to receive satellite radio by converting your phone in to a Sirius XM radio tuner.
The SkyDock is a dock that you connect your iPhone to. Once connected you load up an iPhone app that gives you full access to the Sirius XM lineup. Previous apps omit several key stations.
The dock is powered by the lighter socket in your car and keeps the unit and the phone powered while you drive. Also the SkyDock has a transmitter built in allowing you to tune in your radio in to the signal so you can listen over your stereo system while driving.
The software also has a tagging system built in allowing you to tap a button on the screen if you hear a song you like. When you get the opportunity you can then connect to the iTunes store and choose to download your tagged songs.
The SkyDock will launch soon and cost $120 although there will be a subscription cost to the service too. The only requirements is that you are running OS 3.0 on an iPhone or iPod Touch.
Via: OhGizmo
Am getting an iPhone 3G S soon so I need one of these in my car!