If you are familiar with the tech world, you surely know about the rumors regarding a potential cell phone developed by the Web search giant, Google. Now, Wall Street Journal has some new information about the long-rumored Google’s project.

Quoting sources familiar with the project, Wall Street Journal claims Google already invested hundreds of millions in the project and talked over tech specs with phone manufacturers. Also, the report says the Web search giant developed prototype handsets and has talked with at least to two mobile carriers, T-Mobile USA and Verizon Wireless.

According to the report, a cell phone branded by Google might became a reality as soon as earlier next year.

But what’s in for Google from this project? As Wall Street Journal points out: “the potential to broker ads on the mobile phones, complementing the huge ad business it has built online. Google even envisions a phone service one day that is free of monthly subscription charges and supported entirely through ad revenue, people familiar with the matter say.”

But as the first time when Wall Street Journal wrote about the Google phone (in March this year) Google officials declined to comment on the issue.

Already Google has released some of its services, as Google Search and Gmail for mobile phones, and earlier this month some reports indicated that a mobile version of Google AdSense is in beta test.

Last year, in an interview with Reuters, Eric Schmidt, Google CEO, expressed his believe that mobile phones should be free for the consumers who will accept to watch targeted forms of advertising.

Also last month Wall Street Journal revealed that Google is developing a new search platform for mobile content such as ringtones and downloads and is working with content providers to index materials from entertainment and mobile-media companies.

The goal is to build a large gateway for users to find and buy more rapidly their favorite ringtones, backgrounds, or game.