Former world-champion swimmer Diana Nyad, host of The Savvy Traveler, produced by Minnesota Public Radio, recommends knowing the three rules that gate agents follow.

1. If you fly under the airline's most elite status, you're more likely to get an upgrade.

2. Passengers are put on a list in the order in which they arrive at the gate, so it helps to get there early.

3. A kind and patient approach can't hurt. "Agents have told me on many occasions that they bumped me up because I was so nice," says Nyad. "I would just make my request and say, `I realize you're dealing with a crazy scene here. If there's anything you can do, I'd appreciate it.'"