When you want to check an airfare, you can go to an airlines’ site. Or you can try Kayak or SideStep, which are travel-oriented vertical search engines.
Or now, in 55 U.S. cities, you can test drive Farecast, the plane ticket price predictor site, for cities like New York, Washington, D.C., Atlanta, Chicago, L.A. and San Francisco. It’s first beta site in June only included Seattle and Boston. [Via GigaOM.com.]