Manage your existing Windows systems with Group Policy Preference client side extensions.
These are some serious toys delivering a large punch of power from the suite formerly known as PolicyMaker. You don't need to have Windows Server 2008 or Vista SP1 to use the tools -- now called Group Policy preferences. They include more than 20 new Group Policy client-side extensions, expanding the range of configurable settings in a Group Policy object.
Just go to the Microsoft Download Center and grab them.