NEW YORK--(BUSINESS WIRE)--American Express (NYSE:AXP) today announced the launch of Amex Express Checkout, a first-ever, fast and secure way for U.S. Card Members to check out quickly at participating online merchants by using their americanexpress.com account login. With Amex Express Checkout, Card Members simply use their existing americanexpress.com User ID and Password, and American Express auto-fills the checkout fields with their American Express® Card details and relevant account inform