The news was first reported last night by TechCrunch that Facebook was working on its own phone.  That thought seems a bit silly on many levels, especially since Facebook is currently a software service and they’d have to build or acquire many software and hardware layers to build a successful Phone OS platform.

Facebook is rich and has lots of brain power, but they simply can’t do it on their own in any realistic amount of time.

Just look at Microsoft (GOOG), the biggest, richest and most experienced software company on earth.  It has taken them 18 months to put together their Windows 7 phone OS, which is built on top of a legacy of Zune and Windows Mobile products.

It took both Apple (AAPL) and Google (GOOG) (no slouches) five years to build their mobile platforms into what they are today.  So Facebook is going to build a Facebook phone by themselves and have it ready soon?  Not likely.  So who is going to help them out?

No one.  But just as Google plans to use Facebook’s work to help its cause, Facebook could rift some of Google’s Android…

Erick Tseng, who moved over to Facebook from Android project management, will certainly help there.  Dan Frommer has suggested that Joe Hewitt and Matthew Papakipos are in on the action. These guys are both way too far up the stack to be building a mobile OS, but they could certainly be adding a Facebook layer to someone else’s.

Facebook could even do what Microsoft has done with the Verizon Fascinate and pull out Google’s guts and implant Facebook as the contacts, email, search provider, etc while using Google’s core functionality.

Verizon (VZ) (or whoever) could market this Frankenstein as the “Facebook phone!”  (Or they could call it the Kin).

Speaking of the Kin, Microsoft does own some of Facebook and could use it as a differentiator on its Windows Phone 7 devices, though I imagine the scars from the Kin experiment are far from healing.

In one respect, deeper integration into mobile OSes does make sense.  Facebook can’t grow beyond its current situation as just an app with a few hooks into other apps without some deeper integration.  And Android is the easiest way to build that because of its open nature.   But that’s as close to a reality as I can see this Facebook Phone rumor getting.

Update:
Facebook has said as much to Mashable.

“The story, which originated in Techcrunch, is not accurate. Facebook is not building a phone. Our approach has always been to make phones and apps more social. Current projects include include everything from an HTML5 version of the site to apps on major platforms to full Connect support with SDKs to deeper integrations with some manufacturers.  Our view is that almost all experiences would be better if they were social, so integrating deeply into existing platforms and operating systems is a good way to enable this. For an example, check out Connect for iPhone and the integration we have with contact syncing through our iPhone app.  Another example is the INQ1 phone with Facebook integration (the first so-called ‘Facebook Phone’). The people mentioned in the story are working on these projects. The bottom line is that whenever we work on a deep integration, people want to call it a “Facebook Phone” because that’s such an attractive soundbite, but building phones is just not what we do.”