Kayak, a so-called meta search engine for the travel industry, has come out of nowhere and grabbed market share from the big online agencies.

FORBES: Travel Web Sites Get Personal

These are "meta search" fare sites, and although they don't offer quite the travel date flexibility as some others do, they often include fares that the airlines sell only on their own websites.

CNN: The skinny on finding airfare deals

Priceline recently announced its acquisition of Kayak, a leading travel search company, which marks its entry into the meta-search space.

FORBES: Breaking Down Priceline's Business And Stock Drivers

However, with the acquisition of Kayak, it marks its entry in the meta-search space.

FORBES: How Can Kayak's Acquisition Fuel Priceline's Growth?

Even if rival travel agencies terminate meta-search contracts with the Norwalk, Conn.

FORBES: Connect

Meta-search remains an integral part of the online travel booking supply chain.

FORBES: How Can Kayak's Acquisition Fuel Priceline's Growth?

The newest player in the flight-and-hotel meta-search market is Hipmunk, a site aimed at de-cluttering travel search results and ranking results by levels of "agony".

BBC: The future of travel search

Think again: Expedia ( EXPE) exited the meta-search market, spinning off TripAdvisor ( TRIP) in an IPO last year, when Priceline and Orbitz ( OWW) balked at disclosing advertising budgets to Expedia.

FORBES: Connect

And meta-search sites like Kayak and Sidestep try to earn a buck helping you find the cheapest among all of the above, plus the sites of airlines, hotels and car rental companies.

FORBES: Priceline Is Not Cheap But May Still Be A Bargain

Between finding a hotel, flight, rental car, cruise, train or tour, savvy travellers use any number of tools, from online travel agencies like Expedia to meta-search websites like Kayak, to fit all the pieces of the puzzle together.

BBC: The future of travel search