It’s hard to keep track of all the Web 2.0 tool appropriate for Education. But this tool that organizes according to Bloom’s Taxonomy does a nice job of showing a select set of tools that can be used at certain levels of thinking. www.usi.edu/distance/bdt.htm
A more exhaustive list of Web 2.0 tools can be found at: www.go2web20.net . This I found great for just exploring and discovering tools that might be useful.
I’m working on a process of completing Needs Analysis before choosing tools. Basing tool selection on needs is, of course, better than having a solution in search of a problem.