Is contagious vomiting hilarious, or do I need counseling?
C'mon, you can't judge me on grounds of taste, it's not applicable to these movies. The one stunt that stood out to me is "Sweatsuit Cocktail", not for Steve-O raising the gross-out stakes, but for the upchuck reactions of everyone around him, particularly the camera man. Now THAT guy has a weak stomach. He seemed to have the lion's share of reactive upchucking throughout the movie.
It's not the act of vomiting, or the vomit itself that sends me into hysterics, so much as how easily a tight group can be sent into fits of hurling by being revolted by some originating, triggering event, which in turn causes a domino effect. The infamous blueberry pie-eating contest scene from "Stand By Me", anyone?