When you need to buy a plane ticket, start at one of the major travel sites like Travelocity or Expedia . These sites allow you to search for flights on specific dates and times, or if your travel dates are flexible, they'll show you the best prices for a range of dates. You can also specify the maximum number of connections you want to make, which airlines you prefer and which service class you would like. Of course, the more specific you are, the higher your price is likely to be. These sites are also a good tool for monitoring fares, as mentioned above.
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If you're flexible, consider booking your fare at the last minute, when airlines often slash prices attempting to sell empty seats. You can find these deals on sites like Site 59 and Best Fares' Snooze You Lose . If you'd prefer to plan further ahead of time, check out other deal sites like Travel Zoo and Cheap Tickets . If you belong to a frequent-flyer program and want to stick with a particular airline, check the special deals section of that airline's site. All of these options and more are available from our Best Fares page.