There has been quite a bit of buzz about a screencast tutorial which teaches RSS concepts. Even if you understand and use RSS, you have to watch RSS in Plain English. The developers have taken a difficult concept, and explained it without the use of any computer screenshots, such that the non technical computer user will understand the concept ... and just an importantly, who one should use RSS.
If you work for a training department, you must watch this video. It demonstrates how one can simplify difficult ideas. I look forward to more tutorials from Commoncraft.