To be honest, I have never wrote a blog before, nor have a read more than a handful.  Just from reading a few others, I can tell that there can definitely be positives to blogging in the classroom.  One of the positives is that students can see what other students are thinking about a certain topic.  If a student is lost on a subject, they can simple read through the other students' blogs to get a better idea of how to an assignment or how to do their own blogging.

One of the negatives to blogging could be that some students are not comfortable sharing their personal feelings with everyone that can read their blogs.  If the topic is some type of health issue, some students might not want to share a personal experience that related to them somehow, in fear of being ridiculed.  Blogging can be bother positive and negative, but personally, I think that the positives out weigh the negatives.

Here is an article I found about a PE teacher who blogged a lot.  This shows the parents what is going on in their children's lives in the content area of Physical Education.  This also shows the students what to expect for future PE classes.  Personally, I think this is a great way for the teacher to be open with the students and parents so everyone is on the same page.

http://fairviewpe.blogspot.com/