A new Web site, yapta.com, tracks airfares to help you find the best deal, even after you’ve bought your ticket. The site provides users with a free downloadable tool that allows you to tag the flights you’re interested in purchasing (or have purchased) when searching online travel and airline sites. Yapta currently tracks fares on the major U.S. carriers and the tagger tool works with the Web sites of Alaska Airlines, JetBlue, American Airlines, Orbitz, Continental Airlines, Ted Airlines, Delta Air Lines, Travelocity, Expedia, United Airlines, Frontier Airlines and US Airways. The tool does not currently work with Firefox, and Macintosh users will need to manually enter the flight information they would like Yapta to track. When the fare goes below the entered price, you will be notified via e-mail that the fare has dropped. If you’ve already purchased a ticket from the airline’s Web site, you can contact the airline for a refund or travel credit, depending on the airline’s refund policy. Tom Romary, president and CEO of Yapta, explains “By enabling travelers to tag the exact flights they want from leading travel sites and receive e-mail alerts when prices drop, we’re providing complete price transparency and presenting them with the opportunity to save a significant amount of money.” The site is still in beta stage and a report we heard from a TV station in San Francisco cautioned that users should double check that the fare that Yapta tags for you is still there before contacting the airline you’re hoping to get credit from — sounds like good advice. Airlines differ in regards to their policy for refunding or crediting the difference between a flight ticket you’ve already purchased and a new, lower fare, so don’t expect miracles, but then again, you might be pleasantly surprised.