Patterns & Practices Guidance Explorer
"Guidance Explorer is a tool to find and use relevant patterns & practices guidance. Guidance Explorer installs with a guidance library including performance and security topics for .NET and ASP.NET applications. The guidance library contains checklists and guidelines covering design, implementation and deployment topics. The tool and the library will evolve over time to include additional types of guidance. "
Check out the Patterns & Practices Guidance Explorer
A very useful tool if you want to make sure the dsign of .Net and ASP.Net applications that you have built is compliant to known patterns & practices. However, note that the tool is still pretty in its early stages, so it is definitely not a panacea to solve all your design problems as yet.