EdX is a joint partnership between The Massachusetts Institute of Technology (MIT) and Harvard University to offer online learning to millions of people around the world. EdX will offer Harvard and MIT classes online for free.
RefSeek's guide to the 25 best online resources for finding free educational videos. With the exception of BrainPOP and Cosmeo, all listed sites offer their extensive video libraries for free and without registration.
I'm a litle embarrassed that this is my first time seeing a "Prezi" and I'm a little crazy excited to try this new tool for whatever I end up teaching next year! How to Create a Prezi Lesson in Less Than 15 Minutes