I've been using Google+ on an off, I finally tried out the "Hangout" function a few weeks ago -- it was very neat.
Circles and "Hangouts" are definitely Google Plus' strong points.
Facebook recently introduced a feature to categorize your "friends" making it easy to hide things from work, family, and acquaintances or any group you want -- similar to circles. They are also working with Skype to introduce a video chat program, if that has not already been implemented.
Social networking is quite an interesting topic. It seems like an unreal phenomenon to have huge sites become so popular.
In July, Facebook reached 750 million 'active' users. An estimated 41.6% of the US population has a Facebook account.
That is truly amazing, a really scary.
First MySpace, than Facebook, what next?