Tom Meltzer: From TED talks to online seminars, video channels crammed with inspirational and thought-provoking lectures are educating us on everything from town planning and depression to body language, animal morality and dangers of sugar in just a few minutes. Here is our pick of the best
Suzanne Moore: Recent news stories involving sexting, wine, toasters, politicians and penises indicate some men need a refresher course, so here are my 10 rules for keeping your penis out of trouble
Deborah Orr: The angry arguments against David Cameron's opt-in filter proposals seem to imply that it's normal to want access to porn, and abnormal not to want access to porn