One of the weed bags are called "It's a weedful life"
Towards the end of the movie, Harold gets something of his stuck to a pole, much like Flick except he got his tongue stuck to the pole.
"Which Karate Kid?"
The Christmas Tree salesmen were named Lamar and Latrell. There was a Lamar Latrell in 'Revenge of the Nerds'
WaffleBot proclaims that he and Kumar are "friends . . . .forever," mimicking Jinx the robot's declaration to Max (Joaquin Phoenix).
Neil Patrick Harris: "I was Carl Jenkins in Starship Troopers"
"Lobby shootout" scene in slowdown sequence
"Like Ryan Gosling in 'The Notebook'"
Harold (John Cho) is referred to as "Sulu". John Cho played Hikaru Sulu in Star Trek.
"It makes 'Avatar' look 'Avatarded.'"
"The only Karate Kid that I know is the Karate Kid with Jackie Chan and Jaden Smith"
Christy mentions that the film was not screened for critics in time for them to review it
Title mentioned during 'Obvious Spoilers' segment of Conan's Video Blog
The movie is played on the TV
The game can be seen playing on a TV set at the party
a clip from the film starring John Cho and Kal Penn is shown
In Platoon a soldier is shot and holding his arms to the sky in slow motion. In A Very Harold & Kumar 3D Christmas Harold's aid does the same thing while being egged on.