Upstart companies like Qixo, SideStep and Mobissimo are developing more sophisticated search engines for the travel space, hoping to cut into the online dominance of Travelocity, Expedia and Orbitz.com.

"You've got a big carrot out there, and big customer pain," explained Mike Sigal, head of sales and marketing for Mobissimo.

Mobissimo, which is in a public testing phase and planning a launch by June, works on a paid referral business, trawling online agencies like Expedia as well as the sites for individual airlines like JetBlue and then taking a referral fees for customer click- throughs.