"Give someone an iPhone 3G Gift Card and when the lucky recipient comes in to redeem it, an Apple Retail Store Specialist will take care of every detail. The Specialist will get your recipient's iPhone 3G up and calling, set up email, and help customize the Home screen, choose some great iPhone applications, personalize ringtones, and find favorite songs."
All you do is add money to the card so it can be used in conjusction with other payment methods, if needed, to pay for a new iPhone.
Great for Christmas!
(Only in the US currently, will soon be avaliable in the UK)