I just setup a test saslauthd server which authenticates against an LDAP server. It works wonderfully!
Now I'm wondering about where to go from here. I've previously setup tinyldap on debian and I would really like to continue using that. However, I really don't have the time required to dedicate maintaining that effort over time in a production environment, so I think I'll use openldap / slapd instead.
There are so many LDAP compatible clients: