Best place to buy iPhone 3GS out of contract?

I want to buy the new iPhone. The ATT store told me once they're in stock full time they can be purchased for $599 and $699 respectively, but I'm not sure about this.

Do Apple stores sell them out of contract or anywhere else? I want to make sure that I get the warranty with it but I don't want to sign a 2 year contract as I already have my own sim card and plan.

Thanks.

Thanks man, I just found out about best buy stocking them before the weekend. Seems that the Apple stores and Best Buy have them in stock to buy for $599 and $699 each now. I might check out that warranty though because I know ATT offer no kind of insurance whatsoever, it's ridiculous!