New Hitchhiker(TM) Tip: Every time you fly there is a 1 in 5 chance that someone on your flight will win a minimum of $400 if they'll just take a different flight. Airlines do their best to estimate how many passengers will be "no-shows." And, sometimes they simply guess wrong. Like when Dunkin Donuts runs out of your favorite blueberry cake donuts. You ask for 2 glazed instead and you smile when she gives you a 3rd one for free. What happens when airlines sell too many tickets has long been kept secret. "What happens in the airport, stays in the airport." The New Hitchhiker lets you in on...