Recently Live webmaster announced its ability to search using your phone by dialing 1-800-CALL-411 as posted on their blog. Some excerpts

We’ve built Live Search 411 to go beyond just finding business information. Because our goal is to help you complete your task, we’ve included features like:

* Connect to any business listing you find-for free
* Receive SMS links to maps, driving directions and traffic conditions (just say “text me the info”)
* Get movie showtimes and even buy tickets over the phone (via our partnership with Fandango)
* Share text messages of business details with friends so they can easily meet you there
* Hear the current weather conditions and the forecast
* Quickly access travel resources like airlines, hotels, and rental cars
* Remember your personalized locations for movie theaters, weather and traffic, and your preferences for receiving text messages.Live Search 411 enables you to do this for free, from any phone in the US. Just call 1-800-CALL-411 (1-800-225-5411) and say where you are and what you’re looking for.

Now on Mobile search technology they also enable voice search on mobile that includes

* Voice input and gas prices in Live Search for Windows Mobile,
* A new beta for BlackBerry devices, and
* Improved mapping and directions in browser-based search for any mobile phone

Details of this voice input

You can now speak your query instead of typing it! Just press the lower left soft-key and say what you want, for example, “Anthony’s Pizza” or “Hardware Stores”. We use advanced voice recognition technology to understand what you’re asking for and give you results.

So far we’ve found it to be a really fast way to get answers for most searches. This feature is currently in beta so let us know how well it works for you! If it doesn’t recognize something you say, of course you can still type it in like you used to.

I have never tried it cause I am not from there and also not sure about yahoo and google features in terms of mobile voice search input.