Blogging In The Classroom

I really have mixed feelings on whether blogs in the classroom are a good idea or not. Obviously, they help students to practice their writing and can express their opinions in a online place, but one of the downfalls I foresee is that the students won't really care about it. At UT many teachers have utilized the discussion board application on Blackboard, where students can make entries and comment on each others and basically have a online discussion. Sounds like a great idea, right? But in my experience it is a waste of time. Blogs and other online discussion tools are only useful if they are taken seriously, like other graded assignments. It's hard to get kids to take online posts seriously because they simply cannot be graded like other writing assignments because they are informal by nature. So, the only thing a teacher can really grade on is whether the students have done it or not and most if not all students will probably just type out a couple of lines that they didn't put any thought to. Therefore it wastes the students time and the teachers by having to grade them.