How are you integrating Active Directory objects (users, groups, etc) into your DDD .NET app? What do your repositories look like and how are you handling LDAP sessions, transactions, and unit of work? Note that I'm not talking about simple authentication/authorization scenarios but rather when the AD objects are part of the core domain model of your app.
I'm working on an application that does provisioning/deprovisioning of AD users and I'm curious what other folks are doing for bringing AD objects into their DDD app. I imagine you're not dragging around the DirectoryEntry object throughout your app but I haven't found any good ORM-type tools for LDAP objects (maybe OLM - Object-LDAP Mapping?).
EDIT: More background info on the question is in this forum post from the Sharp Architecture project.