Once again, Jay Cross points me to a blog post that totally blows me out of the water with its clarity of purpose. He pointed me to Ross Dawson's Trends in the Living Networks: Launching the Web 2.0 Framework. (Just follow the link above to read Ross's description and to download the full four-slide presentation.)
It truly does summarize the role and elements of the Web 2.0 phase of the Internet better then I could ever achieve. Ross captures it all in three slides. It took me 15 slides. I am humbled by greatness.