Two wrecked ships are shown with the registration numbers C57D, a reference to Forbidden Planet (1956). Jayne points out the first one as they explore. The second is the rescue ship, the source of the beacon.
A coffee maker seen in Serenity's dining room/kitchen is an F.A. Porsche Design coffee maker made by Bosch.
The futuristic-looking handcuffs used on River are in fact Clejuso Number 13s, the second heaviest handcuffs currently in production.
When the Operative reviews Mal's file, it shows his Date of Birth as 9/20/2468. 9/20/2002 is the day Firefly premiered.
The keyboard Mal uses to transmit the signal from Mr. Universe's basement is a Micro Innovations Web Office Pro Keyboard.
One of the video clips playing on the monitors in Mr Universe's base is the Blue Sun commercial from the "Firefly" (2002/I) episode "The Message".
This is the first film for which a digital cinema distribution master was made using the new DCI standards using JPEG2000 compression and a 12 bit 4:4:4 XYZ color space.
>>> WARNING: Here Be Spoilers <<<
Trivia items below here contain information that may give away important plot points. You may not want to read any further if you've not already seen this title.
SPOILER: According to the Q&A with Joss Whedon and the cast after the premiere at the Edinburgh International Film Festival, there were at least 20 separate takes of the final make-out scene between Simon and Kaylee in the engine room, with take #20 being the one used in the final cut.
SPOILER: During the funeral scene, Kaylee wears a medallion with the Chinese symbol for marriage.