That's why I carry the American Express cardThere's one class of
privileged iPhone buyers who are going to get all of their money
back: Those who bought the phone with an American Express card.
Extending its usual price-protection policy, the card issuer is
refunding $200 back to anyone who paid the old $599 price for an
iPhone, blogger Muhammad Saleem reports. All they need to do is
call customer service, he writes. (It's not clear what's going
to happen to people who bought the cheaper 4GB iPhone, since
that was discontinued, rather than reduced in price.) Some Visa
and MasterCard issuers have 60-day price-protection policies on
their cards, but for early adopters who waited in line to buy
the iPhone on June 29, that window has already passed. Update:
American Express apparently discontinued its price-matching
benefit last year. Anyone else, like Saleem, luck into a
generous customer-service rep? Another first-hand report after
the jump.  A tipster writes:  I just called AMEX about the $200
iPhone credit at