Facebook moved quickly to quash reports over the weekend that it was secretly building its own mobile phone to blunt the increasing power of the iPhone and Android platforms. But the fuss appears to be a largely semantic one. Facebook is clearly trying to weave the popular social network into the fabric of mobile society. And in doing so it appears headed straight into the ongoing battle for mobile supremacy currently raging among Apple, Google, RIM, Microsoft and others.

Attempting to refute the report on gadget website TechCrunch that Facebook is “building the software for the phone and working with a third party to actually build the hardware,” Facebook spokeswoman Jaime Schopflin told the Wall Street Journal's Digits blog that the company is simply working on "deep integration" intended "to make all phones and apps more social.”

But as Geoffrey A. Fowler notes in his Digits post, Facebook’s head of mobile Erick Tseng – a former member of Google’s Android team – has described Facebook’s mobile efforts as “stepping away from doing just one-off applications ... and towards a platform strategy.” Facebook wants to leverage it's nearly 600 million users, 150 million of which use its mobile apps, to gain a slice of emerging markets that the mobile giants have been jousting over for more than a year. Apple, Google, Microsoft and even RIM – assuming its Blackberry Apps World gets out of the starting gate – have designs on mobile advertising, mobile search, mobile payments and other potentially lucrative arenas.

"All experiences would be better if they were social," Facebook's Schopflin said, "so integrating deeply into existing platforms and operating systems is a good way to enable this.”

The intersection of social networking and mobile technology is turning yesterday's friends – the Facebook iPhone app is a best-seller – into today's fierce rivals.  It's not coincidence that Apple recently announced two social networks, "Ping" for its iTunes store, and "Game Center" for social gaming on the iPhone, without any help from Facebook. Google also has designs on Facebook turf, reportedly working on yet-another social network called, "Google Me," after launching "Google Buzz" as an add-on to Gmail earlier this year.

If you thought the renewal of the old Apple-Microsoft rivalry was making things interesting, just stay tuned in the coming months.