Yahoo’s oneSearch voice search feature for mobile phones, which I’ve been test-driving on my BlackBerry, is now available in the company’s free iPhone app, too. It works surprisingly well for the specific use cases on which Yahoo focused. It’s targeted at travelers searching for flight numbers, locations, Web site names, and local restaurants or businesses.

For now, the app handles your speech as input, but doesn’t talk back to you. It displays search results onscreen, just as if you’d typed in the phrase instead of speaking it. It includes a search box at the top that show’s the app’s interpretation of your spoken words.

Here’s a short tour of what works and what doesn’t:

  • “United Flight 182” — the app said “Listening . . .” until I stopped speaking, and then switched to “Thinking . . .” After nine seconds, it displayed a mobile search result for the correct flight: United Airlines 182, SFO to LAX, Departing May 21, 6:00 am. Arriving May 21, 7:23 am.
  • “McDonald’s” — Yahoo got the word right, but served results near McDonald, California despite the label mcdonald’s in san francisco atop my browser.
  • “Wired magazine” — Awesome. Yahoo floated a $12 subscription offer to the top.
  • “Paul Boutin” – FAIL. Every attempt at pronouncing my name in English or French resulted in Sorry, Request timed out after about 30 seconds.
  • “Paul BOW-tin, VentureBeat.” I tried the most common mangling of my surname used by telemarketers. Yahoo searched for “hall alton venture pete.”
  • “Robert Scoble cellphone” = robert scoville cell phone, no matter how carefully I articulated the “b” in my special talk-radio-guest voice.
  • “Florist, Lewiston, Maine” Score! Yahoo placed a green dial-the-phone link next to the best florist in town. My mom will be pleasantly surprised.

Yahoo doesn’t claim its voice search is great for everything. But as presenters from the company’s search team stressed over and over at a dog-and-pony show Tuesday in San Francisco, many popular searches — especially from mobile phones — aren’t best served by “ten blue links,” but by one good roll-up of relevant information, plus buttons to play videos or dial the phone.

What I’d most like for the next version of the app: Spoken results, so I can talk to Yahoo while driving without having to take my eyes off the road.

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