[caf]

I remember hearing about someone buying a multi-million dollar artwork with their platinum amex once, so it would seem so.

[joshu]

Platinum Amex I doubt. Maybe with a Centurion card.

[patrickgzill]

The so-called "Black Amex" card has been used to purchase a ~$30 million aircraft, according to American Express.

[madh]

Mark Cuban bought a Gulfstream V over the internet with his American Express card.

[gcb]

Only yahoo to create basement dweller millionaires