Kayak returned an intimidating 579 flights, but when I narrowed the trip length to under seven hours, I had 339 flights to choose from. Google doesn't give you the total number of flights it has found, but a quick count showed that it returned somewhat less, though there were still plenty to choose from. Annoyingly, the Google search returned flights whose departure times were well outside the parameters I had set. (That glitch seemed to disappear when I searched using the Chrome browser instead of Firefox.)

Google's layout of potential flights is cleaner and easier to see than Kayak's. Unfortunately, though, it didn't produce the best fares. I found a roundtrip fare on Kayak for $279 on Virgin America. The first flight will depart San Francisco at 5:45 pm; the return will leave O'Hare at 7.30 pm, which is what I had requested. The closest I could get to that fare on Google was $319, but I'd have to catch a 6:30 am flight to do it. Oddly, the Virgin America flights were listed on Google's site, but not their price.

In case you hadn't heard, Google got into the air fare business by buying ITA Software, which sells flight information to many of the popular fare finder sites, including Kayak, Orbitz and Hotwire. To win approval of the deal, Google had to assure federal regulators that it wouldn't stack the deck against rival Web sites, so it will be interesting to see how Google differentiates itself.

For now, I can't recommend Google Flight Search. It's simply not mature enough. However, Google's expertise in Web search is hard to beat, and the company has a record of launching service before they're fully cooked -- and greatly improving them on the fly. I'd be surprised if Flight Search doesn't become more competitive in the not-too-distant future.

San Francisco journalist Bill Snyder writes frequently about business and technology. He welcomes your comments and suggestions. Reach him at bill.snyder@sbcglobal.net. Follow Bill Snyder on Twitter . Follow everything from CIO.com on Twitter