Usabilla was ran usability tests to compare the usability of four travel sites and has posted the results. Their analysis concludes that Expedia gets defeated by its competitors Hotwire, Priceline, and Travelocity on basic usability tasks. Expedia performed the worst in a usability showdown between the four major international travel sites. A total of 148 people participated in this usability test and tried to perform three basic tasks on one of the four websites.
Read the result analysis at the Usabilla blog.