Site 59

What they say:

"Site59.com, a Travelocity company, is the industry leader in deeply-discounted last-minute travel packages. Named for the 59th, or last, minute, our premier packaging technology continuously locates unsold airline seats, hotel rooms, and rental cars, then assembles them into dynamic, real-time packages that can be booked up to 3 hours before departure. Site59 helps smart travelers save up to 70%** off retail prices on the top brand-names in travel."