Yapta.com

Yapta.com is another fare-tracking site that helps users find low airfares and hotel rates. Unlike other travel sites, however, Yapta continues to track prices after you've already purchased your ticket. If the fares in any part of your itinerary drop sufficiently after booking to offset any change or cancellation fees, Yapta.com will notify you so you can obtain refunds or credits on the difference. Users can also track deals on award seats for five major airlines. Experts offer a few caveats, though. Yapta.com isn't a booking site, nor can it help you to get a refund or credit on seats or rooms purchased through other booking sites -- you have to book directly through the hotel or airline to be eligible. There are also relatively few trip-planning tools, like those you might find on full-service travel sites such as Expedia.com. The ability to search for hotel rates has been newly added.

Yapta.com is a relatively new travel site, but it's listed among several "best of" compilations of travel sites. The most helpful of these are found at PC World and Travel and Leisure magazine. Lifehacker also provides a brief and admittedly unscientific comparison review.