Here’s the 116-page document as a PDF (5 megabytes); the original SlideShare link is in the post.
Cobb writes in a clear, calm, non-technical style. He includes a host of examples (highway-safety podcasts that include interviews with truck drivers) . I particulary liked the “possibilities” boxes with a few bullets suggesting applications of each technology.
He also quotes Stephen Downes on differences between groups and networks, a distinction worth keeping in mind:
Groups require unity; networks require diversity.
Groups require coherence;
networks require autonomy.
Groups require privacy or segregation;
networks require openness.
Groups require focus of voice;
networks require interaction.