A Quick Outline
The .NET Guy highlights one of the most useful features of Reflector from a design and understanding APIs point of view. Selecting 'Outline' with only public visability checked on one of your own namespaces can prove very informative.
If you have installed the .NET Reflector Visual Studio add-in you can outline a class by doing the following. Click on Reflector from the Addins main menu (this step will be obsolete in the next release). Right click anywhere inside the class you want to outline (away from any fields or methods) and select 'Reflector.../Outline'. At this point a new tool window should appear showing your outlined class. Dock the window where you want it (I find next to the 'Output' tab works well). At the moment for the tool window position to be saved you will have to exit Reflector before closing Visual Studio.
As you can see there are still a few quirks I need smooth out. Despite this you should find the add-in unobtrusive and a good alternative to an icon on your quick launch bar. If now runs out-of-proc and in theory shouldn't cause any instability of the Visual Studio process. If it does start playing up just kill the 'Reflector.VisualStudio.exe' process and please let me know!
You can find a download link here. Remember to read the readme.txt - I never do ;o)