Scott Nicholson pointed me to this graphic:
http://www.flickr.com/photos/briansolis/2735401175/sizes/l/
It is from two folks working on social networks it appears in the public relations sphere (http://www.briansolis.com/2008/08/introducing-conversation-prism.html). What I like about it is that conversations are in the center (with learning), and then all the technology that enable them.
As I’ve said in my presentations, Wiki’s, Facebook, Blogs, and such are the current instantiation of a much larger phenomenon – the move to conversations. This image does a great job of showing that.