I chose to pick up my iPhone at a local AT&T store rather than an official Apple store. For starters, there are three Apple stores that are between my office and my home and I figured that there'd be less people with the "camp out" mentality at AT&T stores than there would be at Apple.
The flip side to this is that Apple stores are guaranteed to have more iPhones in stock than AT&T stores especially when they announced that they're staying open until midnight tonight. I confirmed with my local Apple store in Atlantic City, NJ that they still had both 4 and 8GB iPhones available for sale as of 11:30pm tonight.
My plan was to try the AT&T stores first, then in the event that I got shut out, I could make my way to the Apple store to pick up an iPhone there.
One mall disadvantage: mall security. I wasn't there long before security informed my that I couldn't take any pictures in the mall whatsoever. Bummer.
The AT&T manager was pleasant and came out to the line periodically to give us updates. He eventually informed our small group that they only had "about 20" iPhones in stock. No details were provided other than that, actual unit counts appear to be a closely held secret. My main concern was the ratio of 4GB to 8GB models that they had. I was reasonably sure that I'd get an 8GB iPhone because I was within the first 10 people in line and AT&T was limiting sales to one unit per person.
The other advantage to my particular AT&T store was that it was located in a mall which protected us from the humid and muggy temperatures and the looming threat of a thunder storms outside. At about 5:30pm we were moved from a remote line to a line closer to the store, then at exactly 6:00 pm we were allowed to enter the store two at a time.
When I got into the store a small amount of accessories were set up (mostly cases from Griffin) on a rotating rack, as well as Apple earbuds and docking cables. They did not have the Apple Bluetooth headset in stock. I purchased two 8GB units, with my cousin as the other warm body, and after having to pre-clear my credit application in the AT&T store (Apple doesn't require this) I was on my way home to open the box and take lots of pictures.
What was your iDay experience like?