I bought at AT&T store. The guy had NO Clue how to activate with a deposit! He said you pay the deposit online but that was not true. I had to go back to the store and pay the deposit there and you get a ore-approved credit number that you type into iTunes. Once that was done, it was easy. I love this iPhone!My first iPhone I bought at the Apple store last summer and it still works perfectly.
The second one that I bought was from the AT&T store. I bought this phone from AT&T simply because it was closer to me than driving across town to the Apple store. I know that if I have a problem with this iPhone, I can just bring it to the Apple store and they will take care of it because it is under warranty just like my Apple store bought iPhone. No matter where you buy it, you can still take it to the Apple store if you have a problenm just like with an iPod or computer. Apple takes care of things.
The only drawback at the AT&T store was that they weren't very knowledgeable about iTunes and how to activate it as a GoPhone and what plans were even offered for iPhones.