Trivia: When Agent Strahm is in his head box trap screaming, there is a lot of flash-cutting, including a shot of an outtake of the actor smiling with a towel in the cube and staff around him. Happens exactly at 9:52:370 into the movie, or frame 14203. VERY fast and easy to miss.
Trivia: When the credits have finished rolling there is a garbled radio transmission of what sounds like Rob saying "Help us." But when played in reverse you can clearly hear him saying "It's still alive."
Trivia: The recipient on the envelope is Dr. Uroff-Koltoff. "Uroff-Koltoff" was also the name of the ship in the "Patient X" episode. (01:29:05)
Trivia: Philip Seymour Hoffman was the only actor who knew whether or not Father Flynn was actually guilty.
Trivia: When Jerry and Rachel are in the Circuit City, there is a poster for Disturbia, a movie that starred Shia LaBeouf and was directed by D.J. Caruso, who directed this film.
Trivia: Laura Harring, who plays Shannyn Sossamon's mother, is only 14 years older than Sossamon.
Trivia: Elliot's line, "Be scientific, douchebag" was ad-libbed by Mark Wahlberg.