Was looking at http://catb.org/~esr/writings/unix-koans/
Eric Raymond's site recently, and reading his gun nut pages was
reminded of the time I shot the SF police simulator with the cypherpunks.
(This would have been 1998-2003 when I flew up to Silly Valley a week per month, and was an active member of the cypherpunks mailing list.) This is a pneumatic gun (with recoil) that works with a large screen video to simulate various shoot / don't shoot situations.

I got a guy who pulls a shotgun from his car during a traffic stop. I got blown away, and also caught the web of my hand between thumb and trigger finger in the gun's action. (In real life) That hurt.

Another fellow had a scenario where you confronted a guy with a knife and a baby. "Drop the baby!" shouted by a grizzled engineer is pretty comical if you're not the one playing cop. It was very engaging when you were doing it.