Thing 19

For this Thing, I explored classroom20.com and was already familiar with Yelp and IMDB. I found that classroom20.com was much more focused on education, as one might expect, and that made things much easier when it came to looking for topics that were actually useful. There is a lot of advice for new teachers, as well as a significant amount of encouragement. Finding material that is relevant isn't too difficult at classroom20.
I never really thought of Yelp as a social networking site, but after thinking about it, it really is. It enables people to view the opinions of others about particular businesses. Its sort of like Twitter, but focused on individual businesses rather than individual people.
I don't really know if I'd consider IMDB to be a social networking site because of the nature of the site. Sure, people can comment, but the focus of the site is really the movies themselves and maintaining a database of the movie and its content/actors.

As for the actual assignment:

Classroom20 is a good resource for advice from real teachers who experience what you experience.

I'm not a member of ANY online communities, including facebook and twitter, and I will be keeping it that way. I have an Edmodo account in order to upload tutorials/examples for my students, but its nothing more than a drop box and I do not use it for anything social.

I will not be joining any online communities.

I am not interested in any of them either. While classroom20 might be a good resource, I can just as easily ask my co-workers and get similar answers from people who actually know me.