I will hang in with BookLikes until the bitter end, but just in case...
Leafmarks - woefully out of date, but I'm there.
The Reading Room - I know next to nothing about this place. I believe I set up an account there during the Great Goodreads Exodus, imported my books and have done little with it since then.
Tumblr - not book related, but I am there every day, so I can be reached there if need be.
I hate that I feel this is necessary. :(