As illustrated (I hope) by IRIS blogs, You Tube CAN be educational (although I am prepared to bet quite a lot that most people aren't being much educated while logged on to on the site). 

I recently learned from You Tube, that a there is new doc out from photographer extraordinaire, Yann Arthus-Bertrand, called HOME. You can watch HOME on You Tube for a few more days. If you don't know about his book, the Earth from Above, please, do check it out - it's amazing.

Dawn R. Bazely