In response to an email asking about using blogs in the classroom, I wrote back a sort of long-winded reply. I'll post my reply here in case it could be useful info to anyone else.
I love and adore using blogs with my students. In my experience, writing, revising and peer editing within the blog structure has particularly helped their writing skills. So, I've used blogs in that way. I've also had success with journaling in blogs. This semester, my 9th graders are creating big, semester-long projects, and they are using the blogs to sort of document the thought process and give and receive feedback/thoughts from peers. Teenagers are so self-conscious, I find the lack of face-to-face contact adds dramatically to the strength and effectiveness of peer editing and review.
I've done both public and private blogs. While I'd like all students blogs to be open to the public, there are some legal and protection issues involved. I try new ways each time, but in Livejournal, I allow students to use their real names and post so that only their "friends" can see. Everyone in the class is on everyone else's "friend" list. This is helpful to everyone because by clicking on the "friend" link on one's own page, you can easily see new posts without clicking through a bunch of links or starting a Bloglines account.
I've also used Blogger. I like the templates better, and kids can create their own links outside of the ones created inside posts (unlike in Livejournal). The drawback is that Blogger doesn't have an easy way to make them private. So, I ask each student to come up with a pen name and sign a contract stating that they are never to mention real names, location, school name, etc.
Class interaction on blogs is awesome, especially if you bring together multiple sections of the same course. You can do all that with private blogs. However, to me, blogging is essentially a public act, and I think the act of public publication makes kids take themselves and their writing more seriously.
I'll end with one big positive and one big negative. First, the positive. Blogs allow kids that are not normally popular, not normally sought out, to really shine. All of a sudden, your blond cheerleader is constantly running over to the dorky kid in glasses because she, like, really wants a cool emoticon or avatar. Your quiet, sci-fi and fantasy loving tech-nerds come to life and interact with the class in a new way while getting a chance to show off their skills. My students have known each other since birth, so mixing up the social pecking order is a good, good thing. And finally, the negative. I wish I could do more with blogs, but I constantly run into the wall that is lack of access. My school is lucky to have what it does, but blogging, to my mind, requires regularity. When you can only access computer labs or laptops at odd times or infrequently, I think it is very hard for students to build blogging skills and really get something out of the medium.
That said, I keep trying blogs out, and I learn something new with each experience. They do too, I imagine.
I forgot to mention one long-term positive I recently had the pleasure of experiencing. I helped Taiwanese Superhero set up a blog and showed her some student blogs during an intensely boring meeting before the school year started. She loved the medium right away and started using blogs with both her general and remedial classes. All of our 9th graders did their research "papers" on blogs. So this semester, I got several of her students, and she got several of mine. The first day we went in the lab to learn about blogs and get set up, her students from last semester proudly proclaimed their expertise, showed off their lengthy blog writing to the class and helped assist other students with starting their blogs.
If every teacher used blogs, our kids could really have a kick-butt record of their progress in writing and in high school. Maybe they would continue to comment on the work of kids who aren't in their classes anymore. Maybe it could be common ground between teachers and subjects. Maybe it could be dreamy.