Literate programming ( http://www.literateprogramming.com  ) is a way of describing algorithms and programs invented by the the mythical D. Knuth (famous CWEB application). The nice thing about CWEB is that both code and documentation live in the same document. To compile the code, the tool reassembles the code snippets and compiles it. Therefore, you can verify that all the examples in your documentation are compilable. Sadly, the (excellent) C# documentation does not support literate programming... well now it does.

NLiterate is a small application that parses the XML documentation file, reassembles code section and compiles them. This gives you an automated way of testing all your documentation examples. I'll be posting the source soon.