Ben talks about writing Managed Spy++

Ben has written a great article for the April issue of MSDN magazine. You can see it online here. Basically the idea was to write a tool that would allow you to inspect properties and events while your form is running. This tool can be quite handy for debugging layout if you want to see what's inside of what, etc.

Also if you're curious about learning managed c++, the ManagedSpyLib is a good code sample to start from.