This interesting website “History and Evolution of Social media” covers 9 major social media topics:  Precursors to Social Media, early Social Media, Advances, Niche Networks, News & Bookmarking, Real Time Updates, Lifestreaming and Lifecasting, Concerns and Criticisms and the Role of Social Media in Pop Culture.  This article was found on an interesting website called webdesignerdepot

Louise, Youth Librarian, Manly Library (from a news item on a SLNSW e-list)