After a short period of calm, the allegedly mobile phone branded by Google, or GPhone if you prefer, is again in the spotlight. This time it all started with a post from Engadget, who claims to have confirmations from “a number of very trustworthy sources’ about Google’s mobile plans. And it's not just a simple mobile phone branded by Google, it seems to be powered by a so-called Google OS.

“Namely, Google's mobile device platform is well on its way, and will be announced in the very near future. We understand that the "Gphone OS" (our name for it, not theirs) began development after Google's very quiet 2005 acquisition of mobile software company Android, started by Danger cofounder and former-prez / CEO Andy Rubin. At Google, Andy's team has developed a Linux-based mobile device OS (no surprise) which they're currently shopping around to handset makers and carriers on the premise of providing a flexible, customizable system -- with really great Google integration, of course.” wrote Engadget.

According to Engadget, if the latest rumors will prove to be true, we should expect the GPhone as early as the beginning of the next month.

Though, Engadget is not the only one reporting about Google Phone. For example Crunchgear.com claim to have an insider tip from HTC, the company who will be the phone maker.

“Google is currently assessing over twenty HTC models and refining its final handset design and will create a special version of Google Maps, compatible with built-in GPS, and compatibility with Gmail and the calendar app. There is also some talk that Samsung will be releasing gPhone handsets as well, but that has not been confirmed.” wrote John Biggs.

In fact, GPhone is an old rumor, but Google never denied its highly interest for the mobile market.

The first rumors about a Google phone have emerged last year in December, when it was reported that Google seems to be interested in developing a “branded Google phone”. Allegedly Google has held talks with Orange about a multi-billion-dollar partnership to create a 'Google phone' which makes it easy to search the web.

Earlier this month, Wall Street Journal claimed to had some new information about the long-rumored Google’s project.

Quoting sources familiar with the project, Wall Street Journal said 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.

Also in July 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.

Also, in April this year, Gene Munster, analyst at Pipe Jaffray, dismissed the rumors about a Google phone. In a research note he claimed that Google is working to develop software for mobile phones, not a mobile phone. According to Munster’s note, the software is intended for web searches and for managing location-finding services on cell phones, including iPhone. "We believe Google is working with, not against, Apple in the mobile world," Munster said, quoted by Reuters.

* The picture is for illustrating purposes only