Orbitz has a Deal Detector that lets you register a price you want, then alerts you if it shows up.

If you ve seen The Roaming Gnome, you know that Travelocity is one of the big players in discount air travel, along with Expedia and Orbitz. Priceline is also a competitor, but we suggest round the world air tickets you focus on the offerings of the Big Three to get your best deal.
Orbitz has a Deal Detector that lets you register a price you want, then alerts you if it shows up. Travelocity has a Fare Watcher function that alerts when prices change on a route. You need to do the work yourself at Expeida.
Travelocity and Orbitz let you know when the lowest prices are available. They ll even search alternative airports near your destination a key money-saver. So if your schedule is flexible and/or you don t mind a little extra driving to and from your vacation home you can take advantage of some great far-off departure dates OR a just-around-the-corner special.
Beware round the world air tickets of Consolidators - A consolidator negotiates bulk contracts with travel suppliers and then sells those services to travel agents or the general public. Although they were once a source for good values, today the savings over published fares are often small, and restrictions can be high. Look before you buy!
Membership Has Its Privileges Membership in a travel club is usually priced modestly…often under $100. In exchange for your membership fee, you ll receive information about dirt-cheap, round the world air tickets rock-bottom unpublished fares.