Great travel site - Kayak's one of my favorite travel sites. It's very useful for searching for flights, hotels, cars, cruises, deals, and so forth... With flights, for example, it searches all of the airline sites themselves as well as the "discount" sites -- Expedia, Travelocity, Hotwire, Priceline, and Expedia. There are of course some other sites that are good too, but one that's worth checking out in conjunction with kayak is http://www.yapta.com. Book the flights at the best fare with Kayak, and then register your flights with Yapta; if the fare drops even further, they refund you the difference! It's great.