So, you never think your teachers will blog. Don't worry. Just have them send an email to post@posterous.com -- they will be replied with a website made automatically with their email. They can then just email it from then on and it updates automatically.
Don't tell the teachers but they ARE blogging. Shhhh! Just say it makes a cute website they can customize. Tell them it is a blog at the end of the year!
This is from Doug Belshaw aka Mr. Amazing in my book. I learn so much from him!