Ari Graynor (Caroline) improvised her whole speech at the Port Authority when Kevin Corrigan decided he wouldn't say a word during his scene.
The title character's names are a reference to Nick & Nora Charles, the characters in the 'Thin Man' series of films based on Dashiell Hammett's book.
Norah is a Jewish girl attending a Catholic high school. This is explained in the book that Norah wants to attend any school Caroline does, but due to Caroline's obnoxious behavior, she's kicked out of every school she's been to and is only accepted at a Catholic school.
The film originally opened at The Jerkoffs show where Norah first meets Nick. All prior scenes (including Nick leaving a voicemail on Tris' phone, the scenes with Norah, Caroline, and Tris at the Catholic school, etc.) were re-shoots filmed six months after principal production was wrapped.
Nick's cellphone ring tone is "Boys Don't Cry" by The Cure. (The lyrics tell the story of a man who has given up trying to regain the love of a girl that he has lost, and tries to disguise his true emotional state by "laughing, hiding the tears in [his] eyes, 'cause boys don't cry".)
Lorene Scafaria: The screenwriter is the drunk woman who, with Seth Meyers, believe that Nick's Yugo is a cab.
Rachel Cohn, David Levithan: The authors of the novel are in the background of the Veselka diner scene, sitting at a table.