BOSTON -- There are hundreds of travel Web sites out there, but here's one that will help you squeeze the most out of your frequent flyer miles.

MileMaven.com searches bonus mile promotions for more than 300 airlines and frequent flyer programs.

Some airlines request fliers to register for bonus miles before they take a flight. This site will show you exactly what the promotions are and which flights they are good for. It could mean the difference between earning 9,000 miles and earning 27,000 miles.

You can enter a departure and destination airport and search for mileage promotions that fit a specific route. The site also has a mileage calculator to help you figure out how many miles you'll accrue on each leg of your trip.