Looks like today is Education Day on Geekman.com. Mashable has a fascinating list of 100+ Online Resources That Are Transforming Education.
MIT OpenCourseWare and Stanford eCorner are leading examples of free online content from top universities. Tools for publishing (and charging for) online educational content include Faculte.com, uDemy.com, Videolla.com, LearnOutLoud and LeapingBrain.com. Youtube.EDU and iTunes U are general purpose content distribution hubs. OERCommons.org is a search engine for open-licensed content. Sites like About.com, HubPages, Instructibles, AssociatedContent and eHow collect practical advice on everyday topics.