Trivia: On the 13th of December, 2005, Stanley "Tookie" Williams was executed in California. In a strange coincidence the date of his execution is the same as Jamie Foxx's (who portrayed Stan Williams in the film) birthday.
Trivia: The producers had asked porn star Jenna Jameson to appear in the movie, and she agreed. However, she wanted a larger role, that of Danielle, played by Elisha Cuthbert. The producers declined, and Jenna lost the role she was offered. (source: Elisha Cuthbert, speaking on "Lovelines" radio program.).
Trivia: When Miles is stealing money from his mother he looks at the pictures on her dresser. One of the pictures is of Miles and his Dad. It is actually Miles real dad. Miles is played by Paul Giamatti and his dad is Bart Giamatti former Commissioner of Baseball. That is who is in the picture smiling with Miles.
Trivia: In the original script the movie was supposed to be set in New York City, but after the September 11 attacks the location was moved to Baltimore.
Trivia: When Crichton talks to "Harvey" (Scorpius in his head) for the first time in the movie, Scorpius is dressed like Einstein. There is a blackboard with equations on it. One of them is "e = MC hammer". (00:21:30)
Trivia: Michael Caine, who plays Henry Lair, is only 10 years older than his on-screen son Christopher Walken (Turner Lair).
Trivia: Although they play father and daughter in this film, John Turturro (born 1957) is only seven years older than Monica Bellucci (born 1964).
Trivia: Even though Angelina Jolie plays Colin Farrell's mother in the movie, she is only a year older than Farrell.
Trivia: Natalie Portman considers this movie to be her first one that helped her get away from her "Star Wars image".