Trivia: This is for the trailer rather than for the final film, but worth a look. At 1:33 in the trailer, just after seeing Rorschach slam someone against a wall, we see another fight. Pause it and look at the guy in black - he's holding a walkie-talkie, which in the next shot becomes a gun. This is only trivia, not a mistake, because it's only valid for the trailer. The MPAA don't allow guns to be pointed at the screen in trailers, so Zack Snyder, in a tribute to the infamous gun-editing from E.T., replaced the gun in that one shot with a walkie-talkie. (00:01:30)
Trivia: When Carl's house begins to lift and the little girl looks out her window, the Luxo ball from Pixar's other films is seen in her room.
Trivia: Brendan Fraser has a brief uncredited role as Sgt. Stone, during Duke's and Ripcord's training. (00:31:05)
Trivia: During the flashback scene with Tallahassee and the dog, that dog is Abigail Breslin's dog in real life.
Trivia: During the Battle of Vulcan, as Sulu goes under a piece of another starship, you can see R2-D2 go flying past just over his shoulder. (00:47:35)