Essentially, if you've got blogging turned on your Tiger server, every user you create will get a folder inside their home folder for their blog posts, and any text file they put in there (whether manually, through a web interface or via the Atom API), will appear as a post on their blog.
Tom very neatly explains the significance of Apple including blogging in Mac OS X Tiger server. This is exactly what I want to do at Lewis. Create accounts for a bunch of 5th graders on the server, and in the process have blogs enabled for them. I like the fact that it is based on Blosxom. That is the blogging software that Tom uses. I use it locally on my Powerbook for note taking at meetings. It is a great little application.
At Lewis this summer we are moving all our iMacs to OS X Panther. Our school district IT department is installing an X Serve. We will have logins for our 4th and 5th grade students. Am looking forward to next summer and upgrading to Tiger.