I don't use the current glob of social media. You know, Facebooks and Twitters. I guess there is some correlation between my eschewing of short form narrative and these short form communications.
In all this, I have deep mistrust of Google and others who collect info on me. I have less trouble with Apple and Amazon (the way I use Amazon).
But I do have one company that I use that does have some social infrastructure: Netflix. I was one of the first users of Netflix (and Greencine) as soon as it was possible and have been satisfied with the DVD mailing service. It has become a substitute for what previously was a tedious Bittorrent process among cineasts.
I don't write comments in Netflix, but I do rate films there for the recommendation service. You are welcome to be a friend on Netflix if you have a suggestion for a film. I get all my best experiences these days from such suggestions.
I am in China and the authorities here completely block access to the site, so I cannot check details. And if the process requires me to approve an invitation, that will have to wait until June (2012, if you are reading this later). But if you want to try, I suppose my identifier is tedg at alum dot mit dot edu.