Google's rumored GPhone remains something of a mystery, but the tale has a new chapter with word surfacing that the search giant has filed a patent for mobile commerce.

According to a PC World story, Google has filed a patent seeking to protect technology that would allow users to pay for goods from vending machines and retailers via text message or SMS.

While Google would not comment on the service dubbed GPay, the filing has fueled speculation that the company is working on its own phone, known as the GPhone.

According to a report in The Boston Globe, the GPhone is real. That story details research being conducted by Rich Miner, a Google employee who is sometimes described as the company's VP of wireless. According to the story, Miner is a "technical staff member" at Google, who has demonstrated the GPhone for a handful of entrepreneurs and venture capitalists.