I can see how students and teachers could use Blogger to collaborate. The teachers in our school have used this to collaborate on a book study before.

School link:
http://www.roanokecityschools.org/education/school/school.php?sectionid=2&linkid=nav-menu-container-4-4939

Google Blogger could be used with students as a way to brainstorm a topic and get everyone to share their thoughts! What a way to get students involved!