A common question about Visual Studio windows is how to get information about them. It happens that the automation model uses the same class (EnvDTE.Window) for documents and toolwindows, so the first question is how to differentiate both. And once you know that it is a toolwindow, which one is it? It happens that you have the Kind property, but also the hidden Type property. And the Guids that identify toolwindows types are scattered among two assemblies (EnvDTE and EnvDTE80), with different class names, and even in different constant groups in the same class. My new article tries to explain all this:

HOWTO: Getting information about Visual Studio windows from an add-in
http://www.mztools.com/articles/2009/MZ2009010.aspx