The airlines have a secret. Actually, they have several, but this one's the most useful: In many cases, you can buy a first-class ticket for little more than the walkup coach fare. The trick is searching for a fare code designation that's called a "Yup" or a "Q-up."

How do you find these magical fares? Check out FareCompare.com, which has an online tool that searches specifically for them. Recently I was able to nab a first-class seat from New York to Atlanta for $649 - only $100 more than the available coach fare. Y- and Q-ups won't be cheap when compared with advance-purchase fares, but they're not much more than a last-minute coach ticket.