SAN FRANCISCO (CNET) -- Google plans to unveil a service called Google Voice on Thursday that indicates Google wants to do with your telephone communications what companies such as Yahoo have done with e-mail.





Google unveils a phone service Thursday in which the search giant acts like a phone middleman.





Google Voice, the new version of the GrandCentral technology Google acquired in July 2007, has the potential to make the search giant a middleman in an important part of people's lives, telephone communications.





With the service, people can pick a new phone number from Google Voice; when others call it, Google can ring all the actual phones a person uses and handle voice mail.





The old version could let people centralize telephone services, screen their calls, and listen to voice mail over the Web.





But the new version offers several significant new features, though. Google now uses its speech-to-text technology to transcribe voice mail, making it possible to search for particular words.





Gmail's contacts now is used to instruct Google Voice how to treat various callers. And Google Voice now can send and receive SMS text messages and set up conference calls.





Existing GrandCentral users should get the option to upgrade Thursday, and Google plans to offer it to the public after "a number of weeks," said Craig Walker, product manager of real-time communications and head of Google Voice.





As interesting as the service itself, perhaps, is that Google plans to offer it at no cost.





Google is in the midst of a profitability push, trying to wring more money from existing sites, adding advertisements to properties such as Google Maps, Finance, and News that previously lacked them, and canceling many projects such as Google Lively that didn't pass financial muster.





With Google Voice, though, the company is showing more of its earlier, more patient approach.





"Our goal is to be able to offer it to people for free," Walker said in an interview at Google's offices here. Asked what the revenue model is for Google Voice, he offered only an indirect answer: "Let's get a bunch of happy users engaged in Google properties and getting their voice mail through this. Google gets value out of having happy Google users."





Money isn't completely absent from the picture. The company does charge for international calls, and it wouldn't rule out advertising in the future.





GrandCentral has appeared largely dormant from the outside since the Google acquisition, leading some to spotlight it as an example of a promising technology that was squelched by an acquisition. But, Walker said, there was plenty of work going on behind the scenes.





"In addition to innovation, there's been a process of getting migrated and integrating with the Google infrastructure," he said.





One big possible difficulty for people could be the issue of changing phone numbers. People's phone numbers can form a piece of their identity, in particular with home phone numbers held for years and number portability making it possible for people to keep their mobile phone numbers even if they change carriers. Even leaving aside the issue of the hassle of changing phone numbers, sharing your Google Voice number means committing your telephony to Google's services.





Another possible hitch is offering phone numbers that match where people actually live or work. Here, Google hopes to have things under control, though there were no numbers in the 415 area code for my test of the service.





"Our goal is to offer numbers to virtually everyone who wants to sign up. There are a finite number of numbers in the U.S., but we haven't reached anywhere near depletion," Walker said. "We hope to have a pretty good footprint (for area code choices) so that people will have really good choices."





Google Voice, hands on





Overall, I found Google Voice to be potentially useful, with the most compelling option the imperfect but still very useful transcription.





The first promise of Google Voice is to simplify your phone communications. You don't have to worry about which number to hand out to
What is the name of Goodle's phone service? When will the service begin? What did the head of Google Voice say? which company was announcing How much will the service cost? When will the service start? what will it cost
Google Voice Thursday "In addition to innovation, there's been a process of getting migrated and integrating with the Google no Thursday no
question: What is the name of Goodle's phone service?, answer: Google Voice | question: When will the service begin?, answer: Thursday | question: What did the head of Google Voice say?, answer: "In addition to innovation, there's been a process of getting migrated and integrating with the | question: which company was announcing, answer: Google | question: How much will the service cost?, answer: no | question: When will the service start?, answer: Thursday | question: what will it cost, answer: no