If you are currently using the free Desired Configuration Monitoring (DCM) solution for SMS 2003 or are evaluating this functionality, there is a great blog on MSDN which digs into the technical details of this software.
In case you are unfamiliar with DCM, this solution will allow you to automate the validation of configuration management data that you are collecting with SMS. DCM also ties into Service Monitoring and Control by utilizing MOM to alert on any “out of compliance” items.
From the documentation, “Desired Configuration Monitoring (DCM) enables you to author desired configuration manifests, and to monitor and report on compliance of your computers against a desired configuration. DCM strengthens the Microsoft systems management platform by checking for undesired configuration changes across multiple configuration sources.”