In 1.05 The Outsider Donny keeps calling Luke "Abercrombie & Fitch". That's an inside joke because Carmack's biggest credit before 'The O.C.' was being an Abercrombie & Fitch model!   In 1.07 The Escape Holly says "He hooks up with everyone,...girls from Notre Dame". Rachel went to high School at Notre Dame, California. Yes another inside joke.   In 1.03 The Gamble, Dawn orders the same drink as her son, Ryan, did in the pilot episode. The drink being a "Seven and Seven".   The theme song of The OC, "California" by Phantom Planet is also used in the film Orange County.   In 1.12 The Secret, in the scene where Mr. Bendis is telling the students what assignments that they have to do he said: "Stephanie and Bobbie, The Prodistenet Refermation. Stephanie are you listening? Stephanie? Miss Savage!" - Stepahanie Savage, is the Supervising Producer for the show! hahaha! that's funny!   1.04 The Debut was originally supposed to be Anna's only appearance on The OC, but Samaire Armstrong's performance was so well-received, that the producers decided to bring her character back.   In 1.16 The Links, Summer says that maybe she'll put a dead frog in Seth's X-Men underoos. This is a reference to the fact that in real life Adam Brody put a dead frog in Rachel Bilson's birthday gift box when they were filming "The Heights". It was from the dissecting scene, and she didn't find it until later on that day.   Drew Fuller was credited as a guest star in one episode but he had no lines, and appeared only briefly.   In 1.22 The L.A., Seth mentions that he hopes Natalie Portman, Keira Knightley, and Kate Bosworth show up at the party. Adam Brody once mentioned in a online chat that those were the women he had crushes on.   In 1.07 The Escape, the song played while Ryan is carrying Marissa out of the alley ("Into Dust"), is the same song played in the pilot when Ryan finds Marissa passed out on her driveway and then carries her to the poolhouse.   Eric Balfour, Alan Dale and Navi Rawat have all appeared on another FOX series, "24", and Balfour appeared on "Buffy the Vampire Slayer" while Rawat appeared on its spin-off "Angel."   In the beginning of Season 1 Summer is only listed as a guest star but she appears in every episode while Jimmy and Luke are in the credits but don't appear in every episode!   In 1.14 The Countdown, Rachel Bilson and Melinda Clarke, were officially added to the regular cast of 'The O.C.', and their names appear in the opening credits beginning with this episode.   In 1.14 The Countdown, Adam Brody mentions the scene where he's claustrophobic, in an online chat archived at the FOX official website. Adam said "There's a scene me and Ben did where we're locked in the poolhouse and I get claustrophobic. And so this girl closes the door on me in the scene, and I actually got hit by the door and it really hurt. So when you see that scene in an upcoming episode, you should know it's for real."   In 1.16 The Links, Summer, Seth and Anna are watching TV and the video clip for Enrique Iglesias "Addicted" is on. Although we don't actually get to see the video clip, Mischa Barton stars in that video!   Adam Brody stars in the movie The Ring (2002) and Seth says in one episode "I'm not reading that, that's like The Ring. I don't wanna die."