Think you know what you’re doing every time you engage in social media? Neither do I, and neither do the social media gurus I spoke to about their biggest social networking blunders. In an effort to learn from others’ mistakes, here’s a list of some all star errors in judgment from some social media all stars. I’ll lead off the order by admitting an error of my own.

Last month, Yahoo Mash was shut down before ever leaving beta form. They have not completely abandoned social media. And now, Yahoo has renewed its attempt to making its site more social, with the rolling out a beta of its recently updated “universal profile” system, Thursday.

The Social Media Classroom (SMC) is a new project started by Howard Rheingold which offers an open-source Drupal-based web service to teachers and students for the purpose of introducing social media into the classroom.

Social News websites are very much in fashion nowadays, a social news website is a site where the community members rather than an editor take control of the content and ultimately decide whats hot or not. For bloggers in particular Social News websites can be a great source of traffic if your lucky enough to get an article published on their front page that is. With so many of these sites now available though you might not know about them all, we thought it would be nice to draw your attention to some of them that have become established over time.