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!
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.
The television station in the movie is WJZ in Baltimore, Maryland. Some of the filming was done in the station located on "TV Hill" in West Baltimore.