Well it allows one to configure a pretty comprehensive Address book for a company.
I am using the Fedora Directory Server as an Address book for users outlook, the current "theaddressbook" isn't comprehensive enough and the LDAP contrib "phpldapadmin" doesn't have enough fields in it.
The users a very happy with the FDS on a fedora 6 install, but I want to move it to the SME Server.
Cheers