Are you trying to be funny, HAL?

Way back in the old days, we had a Dummy Operating System... it was just an application that run with an entry in Autoexec.bat and it said weird stuff when you tried to do anything - a "del " would result in a "I won't delete it. Delete it yourself!" and a "copy " would say "Copying is so not original. I don't want to copy. I want to create something new and original."

Today, I came across a dummy ASP.NET error page that said: "System.ServiceModel.FaultException: Unable to cast a spell on class String". After amusing 404 messages, they now come up with funny error pages that look so much like the real thing.