Can I use an AT&T Pay As You Go SIM card in an iPhone?

I know the iPhone uses micro SIM cards and PAYG has those now. I don't necessarily need the data part of the plan anyways, I just want the texting and calling because I always have Wi-Fi wherever I'm (work and home).

Is it possible?

Added (1). Should have been more specific. IPhone 4 or 4s. They DO have SIM card slots. I know this for fact.

Nope.

ATT prohibites an Iphone on their prepaid networks…

No.iPhones do not have an intake place for sim cards.

Yes, a Go-Phone Sim card works for an iPhone 4 or 4S.
On this amazon page: http://www.amazon.com/...003X7INLK/ people are reporting that it has worked for them.

Yes, it will work. You are right, you won't be able to use internet though, unless you are connected to Wi-Fi. I've never seen a Pay As You Go micro SIM card, but if you can't find one, just buy a regular micro SIM card and Pay As You Go SIM card and transfer the Pay As You Go plan to the micro Sim. Voila.