Website: http://www.youtube.com/teachers
Website: http://www.ted.com/
Free iPad app: https://itunes.apple.com/us/app/ted/id376183339?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/ted/id376183339?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.ted.android
Website: http://ed.ted.com/