I have recently upgrated to the new iphone which is fantastic, however with heavy business use i am always charging it. I had a power pack from Battech.co.uk for my HTC that was fantastic to called them to see what they had for the iphone.
This is the product they supply into many retail stores in the UK and its such a cool product...
Battech Store: BATTECH iPOWER 3-in-1 IPOD CHARGER
...it replaces the data cable so all you do is carry this one with you. It is a data cable, chrges the phone and also charges the built in battery that gives you extra emergency power without have a brick in your bag.
