The adaptation of Philip K. Dick's short story "The Impostor" was originally planned to be one segment (about forty minutes) of a three-part science fiction movie. The production company liked the early "dailies" so much, that the idea was fleshed out into a feature length film. The other segments grew into the features Mimic (1997) and Alien Love Triangle (2008).
Spencer Olham is said to be "very good at integral and differential calculus." This is a tongue-in-cheek reference to Gilbert and Sullivan's musical "Pirates of Penzance" from the famously silly patter-song "Modern Major General." (The line from the song is, "I am very good at integral and differential calculus, I know the scientific names of being animalculus...")
A street scene is filmed in a courtyard of Cal Poly Pomona's administration building, the same one used for Jude Law's apartment building in Gattaca (1997). Several students and staff of Cal Poly Pomona were used as extras for this scene.
Originally intended to be Miramax's big Christmas movie for 2001, the film got delayed to January just days before it was set to open due to last-minute edits on Kate and Leopold (2001), which forced that film to take this film's original date.