Authenticate Drupal to OS X Server's Open Directory

These settings worked for OS X Server 10.3 (Panther). Not sure how compatible they are with Tiger and Leopard.

LDAP Integration settings
LDAP Port: 389
Base DN: cn=users,dc=yourdomain,dc=com
UserName attribute: uid

LDAP Groups settings
Groups exist as LDAP entries where a multivalued attribute contains the members' CNs
Nodes containing groups (one per line): cn=groups,dc=,dc=com
Attribute holding group members: memberUid