Simplify your XML Comments!
GhostDoc is a free Visual Studio extension that automatically generates XML documentation comments for methods and properties based on their type, parameters, name, and other contextual information.
When generating documentation for class derived from a base class or for interface implementation (e.g. .NET Framework or your custom framework), GhostDoc will use the documentation that Microsoft or the framework vendor has already written for the base class or interface.
It supports VS2005, VS2008 and VS2010!