We have a test installation of "Moodle" at OSGeo Moodle. Login via LDAP.
Note: the above address does not work. Tested on 12/8/10 by SergiuszPawlowicz.
Requests can be submitted via the SAC Trac.
The login page help text is located here:
Site Administration - Users - Authentication -> page bottom field "Instructions"
Change user access level
Site Administration - Users - Authentication - Browse list of users - it is set under roles. There is a roles setup for the front page and then you can have a different role within each course.