We are currently working on a 150-user Active Directory Migration for a customer. It is necessary for the users and client computers to move into an existing domain, and for security reasons a trust relationship cannot be put in place between the old and new environments. The project involves the design, planning, testing and migration of all users, data and services.
We've also recently successfully audited a landscape of mixed Windows clients (XP, Vista and Windows 7) using a tool deployed via Group Policy. This was carried out without invoking client-side administrative privileges and auto-saved client audit results to a server as .csv files.