Your business meeting ends early and you're ready to head home - but your flight doesn't leave for a while. It's happened to all of us, and it happened to me just the other week.

I arrived at Chicago's O'Hare Airport a couple hours early for my flight back to New York's LaGuardia. It was a busy Monday and I knew standing-by for an early flight would be tight. But I wasn't flying blind.

That morning, I'd logged into one of my new favorite Web sites, ExpertFlyer. I got an inside peek into the airline's inventory for that day and I knew that the earlier flight at 6:20 p.m. had 14 open seats -- which made my chances for getting on that flight pretty good. (Long story short: I was the last guy who made it on.)

In fact, through ExpertFlyer, I knew almost as much about that flight as the gate agent did.

That's important because on any given flight there are dozens of different fares or classes of service and unlocking them can give you the power to optimize your travel experience.

ExpertFlyer allows you to be your own travel agent (though it doesn't book seats) by helping you find the flights that have better chances for upgrades, or search for the fares that allow much more flexibility without much more dough. (Without this, nailing down frequent-flier tickets or upgrades often requires multiple phone calls, numerous Web searches, and too many compromises.)

Get the full story at Fortune

Related Link: ExpertFlyer