I was able to just place an order for pickup using the Apple Store app!
For availability in other stores.. Try this website:
http://milo.com
Seems like a lot of stores have Verizon and Sprint phones in stock... May be it helps people who are interested in those carriers.
It worked. But there were no stores in Orlando with any stock.
Bummer.
Finally worked but what's the point of having this option when there's none available in any Apple store?
Well it looks like no stock for 64GB AT&T. I even entered a random zip code.