Like a lot of frequent travelers, Kevin Pollard relies on the Internet to save money on airfares, hotel rooms and rental cars. The quest generally took him to the Web's most popular travel sites — Orbitz (ORBZ) , Travelocity and Expedia (EXPE) — until he discovered a new breed of specialty search engines that promise to dig up even better bargains.

"I am always looking for something that gets me the best deal out there with the least amount of effort," said Pollard, 56, an international marketing consultant who travels from his Metairie, La. home every other week.

Pollard believes he got just that with Mobissimo (search), which he used to plan two recent trips. The San Mateo-based company and other so-called Internet "travel aggregators" such as SideStep (search), Cheapflights (search), Qixo (search), Kayak and Farechase are hoping to win more converts as people arrange holiday season getaways.

"Many consumers are becoming frustrated with the online travel experience," said Mobissimo co-founder Svetlozar Nestorov. "Our goal is to make it better."

Millions of travelers turn to their computers whenever they plot their itineraries. Forrester Research (search) estimates that 29.4 million U.S. households will use the Internet to book travel in this calendar year, spending $53 billion in the process.

Expedia, Travelocity and Orbitz have helped change the way people book travel by deploying sophisticated travel reservation systems that quote prices from most major airlines, hotels and rental car providers.

"The online agencies really represented 'Travel 1.0' because they democratized the process of booking travel and made it available to all of us," said Phil Carpenter, SideStep's vice president of corporate marketing. "The next generation is represented by the travel search engines. We're 'Travel 2.0.'"

The travel engines say they are more consumer-friendly because they crawl the Web sites of travel suppliers more frequently, generating an even broader array of choices.

After a selection is made, the travel engines send people directly to the supplier's Web site to complete the purchase. They collect referral fees from the travel suppliers, but those commissions generally fall about 50 percent below the costs triggered by a booking at three major online travel agencies — a difference that leads to lower consumer prices.

San Francisco-based Qixo is the only travel engine that charges consumers to use its service.

Besides offering better prices, the search engines say they pull fares from suppliers that aren't represented by the major travel agencies. Several travel engines include fares from JetBlue in their indexes. SideStep, the oldest travel engine, includes the entire inventory of Southwest Airlines, the industry's longtime discount leader.

Neither Southwest nor JetBlue list their fares through the online travel agencies — a void that has prompted many consumers to consistently visit three or four travel Web sites to ensure they are getting the best deal. The travel search engines depict themselves as a one-stop shop that provides a totally transparent window into industry pricing.

The growth prospects of the travel search engines look even brighter now that Internet heavyweights Yahoo Inc. (YHOO) and America Online Inc. are moving into the space.

Yahoo bought Farechase for an undisclosed sum in July and AOL acquired a minority stake in Norwalk, Conn.-based Kayak earlier this month.

But not everyone is convinced that the travel search engines are bound for success.

Although they do offer a few convenient features, the travel engines still haven't proven they will be compelling enough to overcome the higher name recognition and deeper pockets of Expedia, Travelocity and Orbitz, said Forrester Research analyst Henry Harteveldt.

The greater financial resources of the big three online agencies also give them the wherewithal to launch their own search engines if the upstarts become a threat in the next three to six months, Harteveldt said.

Recent market share data illustrate the uphill climb facing the new travel engines.

As of mid-November, the top six travel search engines held a combined 0.42 percent share of all traffic to online travel sites, according to Hitwise, an Internet research firm. In contrast, Expedia, Travelocity and Orbitz held a combined 16 percent share of online travel traffic, Hitwise said.

SideStep believes Hitwise data underestimates the usage of its travel search engine, largely because its users must download software to their computer desktop to find airfares. SideStep says its software has been downloaded more than 7 million times. The company plans to launch a Web version of its airfare search in early January. SideStep already provides Web search of car rentals and hotel rooms.

Meanwhile, the online travel agencies seem intent on preventing the search engines from gaining any more ground than they already have. Travelocity, Orbitz and Expedia are becoming increasingly choosy about which search engines they allow to crawl through the fares on their sites — and even banned some of the engines from using the data.

Mobissimo, for instance, only obtains agency data from Travelocity while SideStep only pulls information from Orbitz. The search engines say they still hope to persuade all the online agencies to share their information, arguing that they can generate more business for everyone involved.

"The travel ecosystem is extremely dynamic," said Mobissimo CEO Beatrice Tarka. "We're just scratching the surface of what we hope to do."