Steve Hargadon identifies a number of key trends in the use of Web 2.0 in education, including...
Trend #1: A New Publishing Revolution.
Trend #2: A Tidal Wave of Information.
Trend #3: Everything Is Becoming Participative.
Trend #8: Social Learning Moves Toward Center Stage.
If you haven't used Diigo (or another social bookmarking tool) before then here's the place for you to try it out.
Don't know where to start? Try finding and adding bookmarks for one or two interesting sites related to the use of Web 2.0 technologies in education. Provide a brief description for each site and don't forget to add at least a couple of tags as well. The workshop conveners can help to get you up and running if you're not sure what to do.