Here’s a nice (bordering on cheesy) video explaining social networks. (via Ziki’s blog)
(If you’re reading this in a reader, you’ll have to click through to this post to see it. Sorry.)
But to continue my FaceBook complaining: The video points out that one of the values of social networks is being able to connect to friends of friends. However, this is an area where you are thwarted by Facebook’s overzealous privacy settings. There are no tools to help you use your network to find people (as LinkedIn does).