Official Tomtom Car Kit for the iPhone.
Doubles up as a Car Charger.
Best price I've seen in a while, and its from Amazon.co.uk direct (not market place).
Alot of people will shun this as they hate the iphone / tomtom app for it... but this is the best price for the item... if you want it.
*Doesn't come with the iphone App (got the app today for £40 using the Argos deal on vouchers)