There was a scene later cut out portraying Aaron as a diabetic. The shot showed him giving himself an insulin injection.
Shane Carruth stated that at most an 80 minute could be made from the footage (the film was 78 minutes). He stated that the shooting ratio was 2:1.
In the scene in which Abe-2 knocks out Abe-1 with nitrous oxide, the container he's holding is actually a rice cooker. Also, we see sleeping Abe's profile, but not standing Abe, because the latter was Shane Carruth standing in for David Sullivan.
The budget for the entire film was around $7000. Most of the money was spent on film stock.
The device in the movie is a person-sized, metal box that hums. One scene features Abe and Aaron standing behind some trees, as they watch themselves enter a U-Haul Storage facility. This scene was filmed in Carrollton, TX (a suburb of Dallas, TX), and in 2005 these trees were cleared to build a Hummer dealership.