Today anyone can have a voice to the world through blogs. Anyone can record their thoughts on anything from the daily events in their lives, to political commentary, to Web 2.0! All a person needs is a computer, an internet connection, and about two minutes to create the blog.
In addition to providing a mechanism for people to communicate with the world, blogs can be an incredibly powerful tools in the classroom. They can be used in a number of different ways. They can provide a platform for teachers to consolidate resources, links, and assignments, much like a course management system. They can serve as a forum for students to reflect on material that they've covered in class; while simultaneously allowing teachers and students to comment and offer feedback on one another's thoughts.
However, blogs don't have to be used in a classroom to be considered educational. I would argue that any blog can be educational. The mere act of informing a reader about a different perspective, culture, or subject can be considered educational. Also, anything such as blogs that get people, especially kids, to write more has educational value.