1. KayakUnlike most of the other websites listed here, Kayak is not a travel agency, but a site that aggregates information from other travel sites and carriers. Advanced filters and sorting options allow you to plan multiple-stop trips easily and view virtually unlimited flight options for free. Flight, hotel and car booking available.
Noteworthy: Kayak has earned numerous accolades, including "Best of the Web" by both BusinessWeek and Forbes.com.
Noteworthy: Card members can earn double reward points by booking travel here.
3. ExpediaExpedia offers full service business travel booking - compare flight, hotel and car fees from hundreds of vendors. Their business travel online center also offers flight status updates, airport guides and text message itineraries.
Noteworthy: Expedia offers its own travel rewards program - Thank You Points - where each dollar spent through the site will earn you one point to be used towards future trips.
4. TravelocityTravelocity offers full service business travel booking - compare car, hotel and flight fees from hundreds of carriers - as well some extras for the business traveler: Store booking preferences, membership accounts and multiple credit cards for faster booking, and check out the travel center for tips, weather information and nearby attractions for most U.S. cities.
Noteworthy: Businesses can sign up for Travelocity Corporate Travel accounts that come with unused ticket tracking and free, 24-hour travel support.
5. OrbitzAnother full-service online booking site, offering flight, hotel and car comparison shopping.
Noteworthy: If your fare drops, Orbitz will send you a cash refund for the difference - automatically. Orbitz also offers rail ticketing through Amtrak to more than 500 destinations.
6. HotwireGet alerts for price reductions on planned trips from this full-service travel site. Comparison shopping available for flights, cars and hotels.
Noteworthy: Check out the Travel Ticker center, where you may find deep discounts on luxury hotels in major cities - it may be a great way to get the company to pay for an upgraded room!
7. PricelineYou've seen the commercials, so you know how it works. If you're booking your own trip, and have time before you travel, the ability to negotiate car, hotel and flight prices can save you (and your company) a lot of money.
Noteworthy: Check out the city guides, powered by Zagat, for meal recommendations in major cities.
8. ComcastPowered by Kayak, Comcast's travel center has a similar look and feel, as well the same search and filtering options. Search hundreds of flight, hotel and car vendors for the lowest price, without additional cost.
9. SideStepWondering why SideStep looks suspiciously like Kayak? They've merged! You'll get the same flight, car, and hotel deals from either site, and can continue booking from both.
10. SouthwestBook air, hotel and car travel at Southwest.com.
Noteworthy: Unfortunately most of the online booking sites do not give Southwest as a travel option, so be sure to go directly to Southwest.com for complete fare comparisons. Travelers will also receive Rapid Rewards credit on eligible hotel chains when booking through Southwest.