Usefulness of nings

I think nings are a useful type of social network because they zero in on specific areas: when you check into your ning (or nings), you are tapping into all sorts of news and information in that area. TeacherLibrarian is going to be an extremely useful link for me as a library science grad student and school librarian but I might want to join a ning about horseback riding, too and perhaps a home gardening ning, as well, because they are also of great interest to me. Here is an online source for finding information on new trends, general news in the field, comments from similarly-interested people, and a forum for sharing one's own ideas on the subject. A ning is a good thing ("Martha" would probably agree).