I use Facebook for posting about events and reading groups. This page, with 5000 followers, is the main one.

On Twitter I follow literary criticism, contemporary novels, insects, and blackwater photography.
A depressing place to go to monitor the h- and i-indices, banes of the UK academic system.
There is a lot of material here, including entire books. If you download something and write a comment, I’ll respond in a day or two.
There is a large community here, but I have not been able to find a use for it.
Samples of the sheet music and photographs
from the novel in progress.
It’s become a dull site since they have begun to clean up their illegal posts.
The site is mainly used by scientists, and has some interesting connections.
Humanities Commons
I’m in several groups in the MLA and CAA, but the place is quiet as a church without mice.