The Limits of Simulation from TheRetirementCafe.com

This'll be in my links post but I thought I would give it some extra emphasis here.  This is a pretty good cover of the boundaries of simulation. 

The Limits of Simulation - Dirk Cotton 

I have now made it my life's goal to show up as a footnote reference in one of Dirk's posts.  Then I will know I have finally arrived.