I'm actually on a number of them. Some, I suppose are social networks, but I don't see them as such. For example, technically, HubPages could be considered a social network, but I don't count it as one. I am on Twitter, LinkedIn, Facebook, Google+, MySpace, and a few other sites like this one. I haven't logged into MySpace in years. I really don't like Twitter, so don't use it so much. LinkedIn, I use, but more for reading some of the interesting articles and making contact with specific individuals. I want to use Google+ more, but just haven't found the time. I haven't fully used Facebook like I should for my own accounts, but I do use it frequently. I'm also a member on a number of sites like HubPages including Helium, AssociatedContent, and Squidoo, but HubPages is the only one I use for myself on a regular basis.