American Airlines has introduced a new feature on its Web site which, business being business, could be copied by competitors. Go to AA.com and shop for the best fare to St. Thomas, and if you're flexible - you can see what's the best price on fares a month out. With a click, you can also search for cheaper fares at nearby airports. Online travel services Expedia and Orbitz also offer the flexible search within-a-month feature, too. Details on American's new features.