Community P2PU http://community.p2pu.org/ Khan Academy translation MOOC study groups Coursera http://coursera-org.meetup.com/ http://www.meetup.com/Coursera/ http://blog.coursera.org/post/59537162597/how-facebook-groups-can-improve-your-experience-with Udacity http://www.meetup.com/Udacity/ http://blog.udacity.com/2012/08/tips-for-organizing-your-udacity-study.html UX http://ux.stackexchange.com/questions/1712/what-is-a-good-way-to-display-infinite-nested-comments