UML Design Patterns for Visual Studio is a project to provide Visual Studio 2010 and Visual Studio 2011 UML toolbox items representing the Gang of Four design patterns. The patterns are split into Creational, Structural and Behavioural sections and includes a supporting UML profile.
This project is essentially a worked example of how to create a new UML toolbox item. I created one to see how to do it, and thought there would some value in completing a set of design patterns and the Gang of Four patterns seemed an obvious place to start.
Web site: http://umldesignpatterns.codeplex.com/