Visible crew/equipment: When Harry and Lloyd first arrive at the Ken Convention in El Paso, there is a shot of the building. Lloyd walks into the building, opening the door. In the reflection, a large light can be seen, as can some of the crew.
Continuity mistake: When Lloyd and Harry are combining drinks to get free beers, when they hand their drinks to the lady in charge of the convention, the amount of foam in the glasses changes as the shot goes between the characters.
Continuity mistake: When Harry and Lloyd are about to drink the blue embalming fluid, look at Lloyd's mouth and you can see his tongue is already blue before he drinks the fluid.