Just saw this on the Microsoft Download Center RSS Feed. Sounds interesting. I wonder if this could help with those scenarios where you are trying to develop an AD-aware solution, but you can't get the neccesary rights on your corporate AD...

For organizations that require flexible support for directory-enabled applications, Microsoft has developed Active Directory Application Mode (ADAM). ADAM is a Lightweight Directory Access Protocol (LDAP) directory service that runs as a user service, rather than as a system service.

Active Directory Application Mode (ADAM) is a part of Microsoft’s fully integrated directory services available with Windows Server 2003, and is built specifically to address directory-enabled application scenarios. ADAM runs as a non-operating-system service, and, as such, it does not require deployment on a domain controller. Running as a non-operating-system service means that multiple instances of ADAM can run concurrently on a single server, and each instance can be configured independently.

Active Directory Application Mode represents a breakthrough in directory services technology that provides flexibility, and helps organizations avoid increased infrastructure costs.

Sounds promising...