Sent to me ( Josh ) from one of our Microsoft consultants....

http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=375f1eea-c60c-4cbe-ac12-1335899c6566

AssemblyToVisio - Visio 2003 UML diagram generator

This tool fulfills the need that arises when one wants to update his/her design docs with the up-to-date UML diagrams which would provide the reader with detailed code map, illustrating the classes, their properties and methods, and relationships between them. Visio 2003 seems as the perfect tool for achieving this, and Visual Studio 2003 even has the reverse-engineering feature which generates the UML shapes out of the C# code. But, VS 2003 only generates classes in so called Model Explorer view, and it doesn't show class relationships (neither inheritance nor references). AssemblyToVisio tries to fix that shortcomings.