4. Look for the best hotel rates
On backbid.com, travelers post their existing hotel reservation data, including the confirmation number, on the site and also e-mail the confirmation number to the website (to further verify your reservation), says a backbid.com spokeswoman. From there, hotels can search this information on backbid.com and offer a better rate or other value-added services if they wish.
Users of tingo.com book a hotel room on that site. If their room rate drops, the site automatically rebooks the reservation at the lower rate and refunds the difference to the traveler's credit card, says a tingo.com spokesman.