Terry Freedman has organized a group of educators (14 I think) to put together a resource summarizing new web developments (Web 2.0) and the role these developments may play in education. The product is an interesting summary being distributed as a pdf.
If you are interested in taking a look, I would recommend downloading the pdf from another site (e.g., edu.blogs.com) because I had difficulty with the Freedman site. An affiliated wiki has also emerged and is fun to explore although very slow.
I am working on my site attempting to add a plugin that allows individual posts to be tagged. So, from now own, I will try to tag my posts. The idea is that a reader can not only locate related posts based on a reader initiated search or using categories, but also based using tags created by the author. Aside from a different way to locate information, the theoretical benefit for readers should be to observe the semantic system the author uses to organize posts. For me (learning aloud), there is also possibly a benefit in making the effort to index the content I record.
A tag cloud should begin to form at the bottom of the sidebar. At this point, I am making no promises regarding the effort required to go back and tag previous posts.