I haven't taken the time to run the code yet either... but I did read the article. The title of the article doesn't even come close to describing the great features used in this article. I realize that EXECUTE AS is the main purpose of the article but this article also does a very, very nice job of providing an introduction to one important type of security. I'd call the article something like "Restricting Access Using EXECUTE AS".
If the code in this article turns out to be as good as the article itself, I'll be making a permanent link to this one. It's short, sweet, and very much to the point.
Well done, Patrick.
--Jeff Moden
Change is inevitable... Change for the better is not.