Trivia: In the episode 'Untouched' Angel asks Cordelia 'Do you have any idea how hard it is to think when you've got a rebar through you?', her reply of 'Actually, I do. Benefits of a Sunnydale education' is a reference to the BTVS episode 'Lover's Walk', in which Cordy falls through a staircase and is impaled on a rebar.
Trivia: Cordelia and Wesley realize that the robbery is happening that night because the door latch is taped down - exactly the same way the guards at the Watergate Hotel realized a robbery was in progress in 1974, which led to President's Nixon's resignation. (00:27:20)
Trivia: When Angel is outside the observatory, he is dressed in the same clothes that James Dean wore in Rebel Without a Cause (a film where there are significant scenes at the same observatory), and Judy has a bit of the Natalie Woods about her too. They are also both set in the 50s.
Trivia: Joss Whedon hints at future events in season 4 during Lindsay's song in "Dead End." It hints about the coming of Jasmine: "The sky's gonna open, People gonna pray and crawl, Gonna rain down fire, Gonna burn us all," and "Pretty as a picture, She is like a golden dream." All references to Jasmine.