SOCIAL MEDIA SITES (Thing 15)

I read about Social Media and Social Networking on Wikipedia and checked out the five sites under Thing 15 — Social Media Sites.  There is a great variety in Social Networking sites from Newsvine which is based on actual news stories and discussion of those, to Reddit which deals with voting on ideas and covering opinions to StumbleUpon which finds websites to match a person to his/her interests.  These are interesting websites and useful to those who want to spend much time chatting on line and sharing their opinions, but not something on which I would like to spend my time.