(1)To freeload, mooch, or borrow with little to no expectation of repayment.
(2) To fall back-assward into good fortune with little-to-no hard work
Mark: Dude, how come Anthony never buys beers?
Jim: Because he's America's guest.
Mark: How did Anthony get a free meal from his boss? He's a totally slacker.
Jim: I'm pretty sure he whipped out his America's Guest Card.
1. To freeload or bum off of friends, with the assumption that you never have to carry any form of payment again, ever.
Guy 1: Dude, can you pick up the beers? I'm a little short.
Guy 2: What the fuck? I paid last time!!
Guy 1: I forgot my wallet, but I do, fortunately, have my America's Guest Card.
Guy 1: What's with Jack? He never pays.
Guy 2: He's America's Guest.