When Steve (Owen Wilson) says "I don't know why the farmer and the cow man can't be friends". It is a reference to the musical Oklahoma!
Features Alana De La Garza's only nude scene.
The Roman numerals above Ben's (Zach Galifianakis') bedroom door are IV XX, this is 4 20 (420). Which goes right along with the Bob Marley poster and bong use.
Melanie Ratcliff made no other movies before or since.