I'm a big fan of the videos from Common Craft. I use them constantly in my classes and workshops. Their newest video is Social Media in Plain English:
I also ran across the Mr. Winkle Wakes video today (hat tip to Jon Becker):
Big Think Edge helps organizations by catalyzing conversation around the topics most critical to 21st century business success. Led by the world’s foremost experts, our dynamic learning programs are short-form, mobile, and immediately actionable.