Other social networking sites.
I am not currently a member of any of these online communities (and most of them I had not even heard of prior to completing this Thing).
I took a peek at WebJunction, which I have heard of but don't believe I've ever actually visited, and it seems that it would be useful and beneficial to join that community. Despite being hesitant to register for any of the previous sites mentioned in the other Things, I will sign up for WebJunction in order to read and participate in the content offered. It would be a site that would serve a purpose for me as an information professional.
As far as the additional social networking sites listed, I checked out BakeSpace and thought it was a neat, fun site full of interesting recipes. I probably won't join it, but it was fun to explore a little (and right on the homepage, I found a nice little peppermint marshmallow recipe that I will have to try out).