I signed up for a Twitter account yesterday so I can stop saying "It sounds stupid" and can either say "Once I used it, it's great," or "Once I used it, I realized it was stupid."
Yesterday, I watched Common Craft's Twitter in Plain English video and highly recommend it. I plan to watch the rest of the videos today. A blog called Please be Quiet I found through Twitter recently posted on using the Plain English explanations to help students and colleagues understand these technologies. I haven't had much luck explaining Web 2.0 stuff to people, so I think I'm going to watch these and carefully take notes.