Barry Williams has a small bandage on his lower lip in this episode and has difficulty saying some words. Greg explains the bandage as he "cut himself shaving", but in reality, Williams had been involved in a minor accident in his Porsche 356C the weekend prior to the episode being filmed and cut his lip when his jaw hit the steering wheel.
The aliens in Bobby's dream sequence were played by two "little people" who were stand-ins for the Brady kids.
In the dream sequence of "Out of This World," the aliens come down in their ship and greet Bobby Brady, declaring to be from the planet Klaputius. This name is a reference to a major character called Klapaucius, an alien cyborg from the science-fiction novel 'The Cyberiad' by Polish writer Stanislaw Lem. Originally published in 1967 the novel had just been re-issued in English translation early in 1974, the year this episode was written and produced.
The TV host named Mario Machado was, in fact, a real TV news personality named Mario Machado. Machado was well-known on local Los Angeles TV, and made history several times. Once was when he became the first consumer affairs reporter in the US, for channel 2 (KNXT, now KCBS). He also gained national attention as a color commentator for CBS Sports, and often appeared as an actor in a number of TV shows, most often playing a news personality.
Jim McDivitt, playing himself, was the first X-15 pilot awarded Astronaut Wings.