Jayma Mays and Adam Campbell, who play brother and sister Lucy and Peter respectively, married in real life shortly after the release of the film. They met while on-set.
(At around 19 mins) In the first cut of the film, the woman who warns Lucy not to enter the wardrobe that leads to "Gnarnia" was completely naked. On the basis of that scene, the MPAA gave the film an R rating. However, the filmmakers had anticipated that the nudity might be an issue, and had filmed the scene where Audra Lynn was wearing a bikini. When they inserted that scene and the board reviewed the film again, they immediately changed its rating to PG-13. The nude scene was reinserted for the "Unrated" DVD.
(At around 8 mins) The high school used for "The Fighting Wolverines" is the same one used for the film Grease (1978).
(At around 33 mins) When the White Bitch "shows off" her White Castle, Kal Penn's character comments, "I feel like I've been there before." This is a nod to Harold & Kumar Go to White Castle (2004), which Penn had starred in three years prior.
In the regular version, Edward says, "Whoa, Stifler's Mom!" when he first sees The White Bitch. In the unrated version, Edward says, "What a M.I.L.F.!" Both lines are references to American Pie (1999). Also, The White Bitch is portrayed by Jennifer Coolidge, who portrayed Stifler's Mom in the American Pie series.