There has been some buzz online about Ello.co, another in the would-be world of anti-Facebooks. Yes, I signed up for it; no, I don't think it'll kill Facebook. I'll be happy if it survives. (Also, I've given away all my invites.)
I'd rather people flock to one of the notes of the distributed Disapora network -- it's technologically more mature -- but after a flurry of activity three years ago, it's largely gone dark. (Anecdotally, the Ello launch has revived interest, if some Twitterers are to be belived.)
A problem that each service has is finding your friends, even if they are subscribed. So these are my accounts; say hello:
Click this to join Diaspora. The schtick is that it's decentralized, without a Big Bad Corporation at the top, so you can also pick a node from this list; it seems some people chose based on what country the host is in -- to take advantage of privacy laws -- or by the quality of service. That's all I know.
I also use Newsblur to manage my RSS (blog and news) feeds, and I have a single follower. (Hello.) If you want to see what I'm reading and promoting, follow me here.
Regular readers: feel free to use the comments to promote your accounts on lessor-known social networks.