I post here a lot but mostly news articles I find interesting. They are not necessarily endorsements. I follow mostly people rather than businesses or organizations.
This is a nice social network it's too bad so few people use it. I like a few communities here. I often post to an archaeology group.
OK, this is more of a profile page but it also has links to the social networks I belong to (some seldom used).
I think it's an international law or something that everyone must have a Facebook account. I do but I really just use it for people I know in real life.