Last week, Google unveiled its much-anticipated social networking platform Google+ (pronounced “Google Plus”). Clearly Google wants to compete with Facebook in this sphere. A lot of details need to be ironed out before we know how successfully it will do so — including at what point people will actually get to join the service — but my early reaction is: Facebook better watch its back.

I was fortunate to receive an invitation to join the “beta” roll out of Google+ and so I’ve had a chance to poke around the platform a bit. Aesthetically, it is clean, clear, and elegant in design. But its real potential to rival Facebook lies in its functionality. The key word here: Circles.

One aspect of Facebook that has always left me cold is that I basically have to choose between sharing something — a link, a video, a photo, a random thought — with either all of my Facebook friends or with none of them. Given Facebook’s popularity, my group of friends on the site includes everyone from my second grade teacher to my college buddies, my current coworkers to my parents’ friends. I like them all, but in different ways and for different reasons, and I’d like to be able to interact with them online in ways that reflect how I’d interact with them in person. Facebook has never given me an easy way to do that.

Now Google has. Circles is an intuitive approach to social sharing that recognizes the fact that we have different groups of people in our lives, and that we communicate with them in different ways. For my money, it is the biggest social networking innovation since chatrooms.

I won’t run through every aspect of the service here — much of which is still being developed and improved upon — but I will say that with +, Google has created something intelligent, special, and new: a platform for online communication that reflects more precisely our natural social preferences and behaviors than anything we’ve seen to date. Going back to my Facebook page feels a bit like popping in a VHS tape now. I’m sold.

The only thing missing? All my friends.