Trivia: Gene Roddenberry created the transporter as an easier (and cheaper) way of getting Enterprise crew members onto a planet's surface, rather than landing the ship on the planet.
Trivia: Originally, Batman villain Two-Face was going to appear in this show and was going to be portrayed by Clint Eastwood. Two-Face's backstory wouldn't have him as an attorney who had acid thrown in his face but instead have him as a news anchor who would have a stage light exploding resulting in his injuries and his transformation into a criminal.
Trivia: A prominent first-season character, Burke Devlin was originally portrayed by actor Mitchell Ryan. However, Ryan was abruptly fired from the show in 1967 due to his alcoholism. Actor Anthony George assumed the remainder of the role until Burke Devlin's death (in a plane crash) in 1968.
The Bring 'Em Back Alive Raid - S1-E26
Trivia: The scene of a German guard in a tower scanning with a spotlight from "Hogan's Heroes" is used to spotlight Moffitt, Hitch, and Tully during their escape.
Trivia: According to his creators, Britt Reid is a descendant of the Lone Ranger's nephew, Dan Reid. Apparently the "masked man syndrome" ran in the family.
Visitors From Beyond the Stars - S1-E18
Trivia: The Time Tunnel Homing Beacon used in "The Revenge of Robin Hood" episode is hanging on the bulkhead by the door of the aliens' spaceship.
The Psychic - S1-E28
Trivia: Watch the drive-in theater marquis when Briggs drives in to pick up his assignment. It reads "Geller and Solow / Spend the Money" - an in-joke reference to producer Bruce Geller and Desilu executive Herb Solow.
Trivia: In the season 5 episode "It Can't Be Five Years?" the woman playing Uncle Bill's secretary is Sebastian Cabot's daughter Annette.