For me social networking is the ability to share information of any nature and in a variety of formats with people all over the world virtually immediately. It allows me to browse and post material.
I use: Facebook for personal, work and study purposes; Google Reader for feeds from blogs related to personal interests, study and work, Delicious (for study), a little Twitter out of curiosity; Flickr (personal and work); Learning Management Systems (Blackboard at RMIT and LMS and Sakai at the University of Melbourne) for work; YouTube for everything including information literacy sessions.
I want to be convinced that social networking is worthwhile and is not just a case of the tail wagging the library dog. I currently work with medical librarians who do not appear to avail themselves of this technology. When I attended a day conference last year I sat next to a librarian from another University who Twittered all day, which I found both intriguing and amusing. I can see the benefits but I want my horizons broadened and see how such technologies could be applied more effectively in a library setting. I also want to debunk the myth that anybody over the age of 40 sees such technology as the work of the Devil.