I think that all of the Web 2.0 tools have the potential to be useful. It just depends on what grade level and subject you are teaching. For an example, kindergarteners and first-graders do not have a lot of computer/technology skills, so I do not think any of the tools will be useful. However, if you're a high school english or social studies meeting I think that Diigo is extremely usefully. I wish I had known about in high school. In reference to teacher professional development, I think that when a teacher uses Web 2.0 and the student's are responsive it is signs of development. I'm not sure how else the two are related. One Web 2.0 tool that I might use is Glogster. It looks simple to use and fun. I think it includes a lot of artistry and individuality which makes projects more fun. It comes in app form which makes it more accessible because most classes are getting class sets of iPads instead of having computer labs. I think having iPads in classrooms nationwide will be life-changing advancement. Textbooks will be stored in them, students will take notes on them, teachers can do grades and lesson plans on them, etc. There'll be no need for lockers or even backpacks. It'll save tons of money on paper. The possibilities are endless.

http://edu.glogster.com/?ref=com