I used Google+. Mostly because its not personal and I dont have to associate with people.
A lot of technical communities are on there and if you are interested in technology, it is an interesting place.
Yesterday Google announced that they had a funky new redesign that people could opt in to.
I did and it was/is horrible. I have backed out to the old style.
Let's just say that I feel less guilty about all the horrible design decisions I have forced upon others on this site.