Using LDAP to dole out WordPress Blogs?

I work at a county education office and we would like to be able to give every teacher in our county a WordPress blog. Is there any way we can do this without manually creating every blog? We have over 4000 teachers, so this would be nearly impossible to do manually. Are there any other institutions that have solved this problem?

We have an LDAP server, so ideally I would love a way to have blogs created on the fly when users are authenticated via LDAP.

Thanks in advance! I am crossing my fingers that someone has thought of this and done it already.

-Kristen