I would like to use a blog in my fourth grade classroom for my students to respond to a novel or a story we are reading during the week. The purpose would be to actively engage my students in the reading. Oftentimes students will not read assigned chapters, but the blog would be something that would hold them accountable for what they gained from their readings. It would be a place to interact about the story. It would be great to assign each student a different question. Each student would then be responsible for posting a response on other students' posts (similar to what we do here).
I like to do a classroom comprehension lesson called Deal-a-Discussion. I group the students up and have them answer various questions as a small group. We then convene as a whole where the groups present to the class and I allow questions, comments, and other dialogue to take place. I do this about once a week. I would love to change it up a bit, and allow students to do this in computer lab at times or even on our classroom laptops. This could be called Blog-a-Discussion!