Check out http://www.go2web20.net/
It has a directory of Web 2.0 tools and resources.
The tags can help you maneuver your way around. Web 2.0 Tools and Applications on one page. Use the list view and get a short description and review so that you can see what people are saying about each one.
Take on the challenge and try out a new tool each week.
You never know, you might find the one tool that you have been looking for to help productivity or creativity for you or for your students.