Trivia: Jennifer Aniston's actual last name is Anastassakis but her family changed it to Aniston when they moved to the United States. If you watch TOW Chandler and Monica's Wedding, Jennifer's actual last name is used for the Greek couple having their wedding in the episode.
Trivia: Matthew Perry's wit is so legendary that the scriptwriters have often incorporated his gags into the show.
Trivia: The Magna-doodle on the door in the boys apartment has a different picture on it every episode. There is usually some tenuous connection between the picture and the plot of the episode.
Trivia: There is only one season where Janice never appears even once: the sixth (she does, however, make a pseudo-appearance when her voice pervades the mixed tape Chandler finds for Monica in the episode where they "make" each other Valentine's Day gifts).
Trivia: In Friends, Joey is an actor on Days of our Lives, a program on which Jennifer Aniston's dad John Aniston plays Victor Kiriakis.
Trivia: In the series 8 episode where Joey tells Rachel he loves her, the gay waiter in the restaurant is the same as the one in the series 9 episode with Phoebe and Joey's 'evil' plan. His name is Sam Pancake and he has worked in two Friends restaurants.
Trivia: The gold frame around the peephole in Monica and Chandler's apartment was originally the frame of a mirror, but was broken before filming began, and it was decided it should be kept anyway.
Trivia: James Michael Tyler was just another extra at first, but since he was the only extra who knew how to use the cappuccino machine he got a bigger part as Gunther.
Trivia: The spare room (Rachel's) in Monica's apartment has a wall right opposite the door, which serves absolutely no purpose except to block the view into the room from the living room. The bedroom set isn't always built, just when needed, so having that wall makes life much easier. It's completely illogical though, as it's too thin to be a supporting wall, and where it is makes getting into the room a pain.
Trivia: Before the title "Friends" was settled, other titles considered for the show were "Friends Like Us," "Six of One," "Across the Hall" and "Insomnia Cafe."
Trivia: Matthew Perry and Bruce Willis starred together in the movie The Whole Nine Yards. While making the movie, Matthew made a bet with Bruce that the movie would open in the top position at the box office. If it did this (which it consequently did) Bruce had to star in an episode of Friends for no fee.
Trivia: Virtually the only time that any apartment doors are locked is when it is important to the episode. For example, Monica's apartment door is always unlocked, even when they go out or she and Chandler are having sex, but in "The One Where Underdog Gets Away" (series 1), it's locked when there is all the "got the keys?" business. Also, Ross' apartment is never locked, except for in "The One With Phoebe's Birthday Dinner" (series 9), when they lock Emma in, and in "The One With The Engagement Picture" (S7 E4) when Phoebe has the key and unlocks the door, then Ross demands it back.