Common Craft (which means Lee and Sachi LeFever) uses, as they say, a simple format and real-world stories to make sense of complex ideas.
Laura Jeffrey at knowledgework posted this Common Craft explanation of Twitter:
Between this, and comments from people like Alan Levine and George Siemens, I’m going to give Twitter a try (though I can be a bit distractable). (My ID, oddly enough, is dave_ferguson.)
Laura’s post reminded me of other effective Common Craft videos, like those on social bookmarking, RSS, and online photo sharing.