Here is a free book from the web that has various projects for teachers using web 2.0 applications.  http://www.ictineducation.org/free-stuff/

• 87 projects.
• 10 further resources.
• 52 applications.
• 94 contributors.
• The benefits of using Web 2.0 applications.
• The challenges of using Web 2.0 applications.
• How the folk who ran these projects handled the issues...
• ... And what they recommend you do if you run them.
• What were the learning outcomes?
• And did I mention that this is free?!