I have had my own issues in locating an upgrading to the iPhone 3G s, apparently there are more just like me out there as Apple has posted an easy locating tool for us to use.  The day the 3G s was released I felt guilty in calling an Apple store to check availability as anyone who has worked in retail knows that release days can be a tediously repetitive day.  You can now check availability of iPhone 3G s’ in Apple stores across the US by visiting their locator site [Here]