Laurie has a picture of Charles Manson over her bed. Later, after Lynda's father tries to kill Loomis, it is revealed that the gun was not loaded - just like the gun Manson follower Squeaky Fromme pointed at President Gerald Ford.
Kristina Klebe knew both Robert Curtis Brown (her father in H2) as well as Nick Mennell (her boyfriend in the first Halloween) before shooting. Rob Zombie had no idea and all the casting was random. Though when he told her about casting her boyfriend in the first film he said he was looking at a few people but he needed someone who could match her height.
Rob Zombie originally stated he would never do a sequel to Halloween (2007), until the studio decided to make it. Then he signed on to write and direct, because he didn't want someone to ruin his vision.
Jeff Daniel Phillips plays two completely different roles in the movie: Howard Boggs and Uncle Seymour Coffins. He is only the third actor to ever play two different roles in the same film in the either Halloween series (the others being Nancy Kyes) and Danielle Harris). Dick Warlock actually plays three different characters, "The Shape" (Michael Myers) and Patrolman #3 (the one that hits the Michael lookalike with his patrol car) in Halloween II (1981) and "Assasin" in Halloween III: Season of the Witch (1982).
In the director's cut, Micheal takes off his mask and yells "Die" before stabbing Dr. Loomis. Based on this scene, it marks the first time ever in the series where Michael Myers actually speaks. This is also the first time the characters face can be seen clearly.
Jesse Dayton recorded an album as Captain Clegg, the album was produced by Rob Zombie and released on August 18, 2009. A music video for the song 'Zombie A Go Go' was directed by Don Swaynos and released online, while several other videos, directed by Zombie, were included on the film's DVD / Blu-Ray release.
Daeg Faerch filmed scenes reprising his role of Young Michael Myers but was replaced and the scenes reshot after it became apparent that Faerch had noticeably grown up since the last installment and no longer looked the same age.
The trivia items below may give away important plot points.
Director's Cut Body count = 20 (plus the two people on screen and the one person off in the opening dream sequence); Theatrical cut = 19. In both cuts, two people are not killed by Michael Myers. There is also a pit of dead bodies that Laurie falls into in the opening sequence, but it is not verified that Michael killed them.
Despite this being Danielle Harris's fourth appearance in a Halloween movie, this is the first in which her character has died. However her previous character Jamie Lloyd was killed off after she was recast.