Blogs cause great interactivity. I have looked at four classmate blogs. Two:
http://jeff-edblog.blogspot.com
http:www.brianhannigan.com/blog
are great resources for teachers. These students have used technology and have some good ideas on how to use it. That's a great help.
Another students not only discusses the privacy,protection issue, but has some ideas on how to address that (http:lksdcmptr.blogspot.com)
Some are just discovering new technology and are a little nervous about using it (much like a student would be)
The point isn't that each blog adds something, it is that the blogs as a whole create a support system for the students, so that they feel they have a friendly (friendly is important) face looking over their shoulder. The cross-pollination of ideas is fantastic, and it gives a teacher the reassurance that if they are confused by a technology, there is help there. It also helps them to understand the technology so that they know what their students are up to. Blogs can really enrich your life, provided you don't just blather on, or permit your students to blather on. There has to be some topic and oversight. But defubutekt shouuld be used.