Facebook says "Come and see what we're building" on January 15 event

Feeling social? Facebook has announced a new event for later in January, with the tagline "Come and see what we're building." The January 15 event is being kept mysterious, with no hints as to the subject in the invite, but that's only likely to stoke speculation in the weeks before then.

One possibility is a new piece or software or services, perhaps building on the Instagram acquisition last year. Facebook also recently announced Poke, its short-messaging and temporary video/photo service, though that was a low-key affair and didn't even warrant an event.

Alternatively, it could be Facebook's much-anticipated and oft-rumored smartphone, chatter around which has been chunnering around the internet for several years. According to the latest batch of here-say, Facebook is using an HTML5 layer on top of an underlying Android OS.

We'll be there to find out exactly what Facebook has in store for us, so join us back on January 15 for all the news! Until then, head over to our CES hub to find out what's monopolizing headlines this week.