The character of Dora Diamond is in part inspired by Franz Kafka's girlfriend late in his life, Dora Dymant. Kafka is mentioned in the English class scene in the movie.
Paul's dorm is called Hunt's Hall. Audiences, especially older, might take this as an allusion to actor Huntz Hall, who was born in New York City (the setting of this film). Huntz played Horace DeBussy "Sach" Jones, a lively buffoon in the Bowery Boys film series, which followed his time as a Dead End Kid in Dead End and in the subsequent Dead End Kids series. It would be an appropriate connotation, in that the Chris, Adam and Noah characters are all buffoons as well as dead end kids (hedonistic young males with no real future).
The scene featuring David Spade was filmed in Toronto's first specialty video store Revue Video. Since the store specializes in films (Foreign Language and Classics) other than the ones feature in the scene, the whole look of the store had to be changed.
Though this was probably done for our benefit, while Dora is running for the "11:50" train, we hear a voice over the P.A. system say that particular train is leaving and from what track it's leaving from. Announcement are not made for departing trains in Grand Central Station.
In the laundry room scene between Paul and Chris, Chris pranks Paul by grilling him about whether he was sleeping with his girlfriend. After fessing up to the prank, Chris says, "I'm just playing with you," but his lips are clearly saying, "I'm just fucking with you" (presumably to retain the PG-13 rating as there is another F-word mention later in the film).
When Dora and Paul are sneaking in to the second act of a show with the smokers, they are seen watching the song "Willkommen" from the show "Cabaret". The song "Willkommen" is the very start of the show, welcoming the viewers to the Cabaret, and would not be seen at the beginning of act two.