http://pluma.sourceforge.net/
http://github.com/sschneid/pluma/tree/master

I, also, have rolled my own app for this purpose. It's meant to be handed off to non-technical (ie: people who don't know and don't care about LDAP internals) to manage directory users.

This is a late response (sorry!), so I'm not sure if it'll help or not.