Enforced Method Acting: Of the unintentional variety. Arguably the funniest moment in the movie is when Patches hits Justin in the head with a wrench. However the rubber wrenches were still pretty hard and it actually cut Justin Long. His initial reaction is quite genuine. The ensuing rolling around and yelling "oh my god" was embellished as he went with it. They subsequently used softer foam rubber wrenches.
Playing Against Type: Jason Bateman's role is one of his few that is not an uptight Straight Man. Also, Ben Stiller's role as White Goodman is a change from his usual roles as a hapless everyman Butt-Monkey, although he plays a similar fitness-obsessed villain in Heavyweights.
Star-Making Role: They're not exactly superstars, but Justin Long, Alan Tudyk, and Joel David Moore were basically unknown before this movie. After they became easily recognized character actors. It also elevated Vince Vaughn to marketable leading man.