iPhone 3G activation will be required at time of purchase: â€œDespite speculation around the Internet to the contrary, iPhone activation must be done at the time of purchase.
AT&T spokesman Mark Siegel confirmed for Macworld that activation must be done at the time of purchase, in-store. Siegel also said that customers could keep their current iPhone or AT&T phone numbers and move to the iPhone 3G when it’s released.
According to the speculation around the Internet, you would be able to purchase a subsidized iPhone 3G and not activate it immediately. After 30 days, AT&T would bring up your account and charge your credit card for the subsidized amount of the phone.