When the doctor is firing Ben he says that one of his excuses could be eating too many Twinkies. This refers to the "Twinkie Defence" as used by Dan White when he was on the trial for the murder of Harvey Milk (San Francisco City Supervisor) and George Moscone (San Francisco City Mayor). This was also referenced by Cordelia in season one's Out of Mind, Out of Sight (1997).
Willow defends her use of magic in a line that was cut due to length: "But it's good-witch power, not bad-witch power. You know, Glinda-in-a-bubble power, not Margaret Hamilton-on-a-bicycle power."
When Dawn and Buffy enter The Magic Box early in the episode, Xander is reading an X-Men comic book. The issue, X-Men #109, is the last in that series before the death of Colossus - an event which later became pivotal to Joss Whedon's run on Astonishing X-Men.
Leland Crooke (Professor Lillian) also plays a recurring character, the demonic Archduke Sebassis, in Joss Whedon's spin-off of this series, "Angel".
The wall painting of the women in Glory's mansion is a reproduction of a painting "Group of Four Nudes" by Tamara de Lempicka