Share 'Ideas needed for High School Web 2.0 Apps Class'

I'm thinking about creating a Web 2.0 Apps class as a semester long elective for high school students. I'm wondering if anyone is already doing this and would be willing to share materials/ideas. I'm also interested in getting ideas for how to structure the class (it runs about 17 weeks). I'm thinking of starting with blogging and having students blog their reflections about each tool they learn…