Web 2.0 tools

I had a look at a few of the web 2.o tools but settled on the area of health and had a look at Medstory. it seemed to be very good - I picked a topic of interest and explored many sites. The only criticism is that a couple of the links I followed were dead but we all have a problem with keeping up with "live" links. The information was plentiful and varied and I could have spent hours hopping from site to site but time constraints meant I couldn't explore as much as I liked. I enjoyed this exercise - I think in a library setting some of these web tools would be useful for students to explore.