At my Introducing Silverlight talk on Saturday, I mentioned Twitter.
Most people in the audience hadn't heard of it and I found it somewhat hard to explain.
Actually, the concept is easy, the purpose of Twitter takes some clarification.
Thankfully, there's this video: "Twitter in Plain English"
Twitter in Plain English from leelefever on Vimeo.
If you like the idea, you can follow my Twitter feed at http://twitter.com/Tableteer and the happenings of the Silverlight DC area community at http://twitter.com/SilverlightDC.