These guys are by far the worst roommates ever!  However, this is one of the best pranks I've seen.  It's pretty much a mixture of the "Mouse Trap" board game and "Jackass."  It seems so simple to set up and yet it's so effective.  Be sure to watch the slow motion portion and you can really see how bad it was.  That poor guy is not walking for the rest of the day.

Ingenious Roommate Trap In Action - Watch More Funny Videos