Facebook has sent out an invitation to the media for a “mobile event” at its Palo Alto, California headquarters on Wednesday November 3. Could this be the unveiling of the much-speculated about Facebook phone? 

You may recall that technology blog TechCrunch reported last month that Facebook was secretly developing a special smartphone.

Facebook then issued a carefully-worded response that said the company was not “building” a phone, but that it had projects focused on “deeper integrations with some manufacturers.”

The response was reminiscent of the tack taken by Google last year when rumors were rampant that it was about to release a smartphone. In January, of course, Google began to sell the Nexus One phone, which it developed alongside handset vendor HTC, on its website.

The Facebook invite provides no details whatsoever other than to say that the event begins at 10:30 am on November 3 and will be followed by lunch.

But the invitation sports an image of two shaded figures alongside what appears to be the old string-and-Dixie-cup phones that kids in treehouses have long used to communicate. One hopes the actual Facebook phone, if there is one, is slightly more high-tech.