I belong to three or four different Nings, which are social networking forums for adults, based around mutual interests. For example, I belong to Joyce Valenza's Teacher/Librarian Ning, the Classroom 2.0 Ning, and a couple others.
The folks at EduBloggerCon, who apparently had a whale of a time, since their enthusiasm has been overwhelming the Ed Tech blogosphere the past week or two, wanted to continue (and share) the experience. Hence, EduBloggerWorld--a great community of high-tech gurus from around the world anxious and willing to share both their experience and knowledge. A great way to network and keep abreast of what's going on in the ed tech world.