Check iPhone 3GS Availability Online First Before You Waste a
TripS  Save yourself some wasted effort by checking on iPhone
3GS availability online first before you get in your car and
head down to the store.  There's no such centralized interface
for AT&T, so who knows how many they have. For a place that
sells phones, they sure don't like to answer them all that
promptly (in our experience). [Apple]