Not without activating it first. It appears that the AT&T requires the iphone to be activated through the online system before it can be used, with any sim card. Some people on forums seemed to have success using their iphone card in other phones though, although they had problems with some features like data and voicemail that use different protocols on the iphone.
Source(s):
http://arstechnica.com/journals/apple.ars/2007/06/27/iphone-faq-smacks-down...

http://forums.wireless.att.com/cng/board/message?board.id=apple&thread....

Permalink | Report

http://www.engadget.com/media/2008/01/att_free2.jpg
iPhones don't work that way. They're tied (in the system) to a SIM card, and will only work with that SIM card, and only once activated. Unless you get one that's unlocked. Honestly, not sure how an unlocked one would work on the AT&T network, though I know that there is an option to get an iPhone on prepaid service if they run the credit evaluation on you and you require a deposit. in your case, you'd need someone else for that though, since you'll need to be at least 18 to even apply for postpaid service.

http://cache.gizmodo.com/assets/resources/2007/07/iPhone-with-SIM.jpg
I know once an iPhone is unlocked, any SIM I've seen tried (none have been AT&T or pre-paid, mind you) will work, but again, not sure how that'd work with AT&T prepaid.
Permalink | Report