Trivia: A little nod to another Blue Sky Studios Production, "Ice Age". When Rodney is looking around Robot city, he comes across a red robot that plays hip-hop. As Rodney walks away nervously ("Uh, n-n-never mind"), pause the frame just before the shot changes and you'll see (on the left) a yellow, mechanical Sid. Sid is the sloth (and the main character) from "Ice Age". (00:15:25)
Trivia: At the very end of the film, when the group uses the Improbability Drive to go to the Restaurant at the End of the Universe, there are a lot of images that flash onto the screen when the drive is activated, so in the other parts of the film. In this case, the very last image shown is the face of Douglas Adams, the creator of the Hitchhiker series.
Trivia: Fantastic Four creator (and Marvel editor-in-chief) Stan Lee has a cameo as Willy Lumpkin, the Four's mailman. It was his only Marvel movie cameo based on an actual comic character.
Trivia: Gene Barry and Ann Robinson, stars of the 1953 version of this movie, make a small cameo in this movie as Mary Ann's parents. They are at the end when the whole family is reunited.