Continuity: Rachel is feeding Peter some dessert, he eats a few bites and remarks about how good it is. The camera pulls back and shows a cake perfectly intact.
Continuity: When Peter is talking to his stepbrother in the kitchen, (before he goes to Hawaii) the cereal in the container on top of the refrigerator changes position several times as does the container after Peter talks about Sarah giving it to him.
Continuity: In the first scene with Peter and Sarah, she is seen with a bobby pin but later on the bobby pin in her hair disappears. Before she leaves you can catch a glimpse of it again.
Revealing mistakes: In the several scenes where Peter and Brian talk over Apple's program called iChat, and the camera focuses on Peter's MacBook, the green light that should be on while the built-in camera is activated is in fact not illuminated.
Continuity: When Peter gets out of Rachel's car after trying to kiss her, Rachel's body is turned in her seat and she is facing him. In the shot where Peter is walking away, she is turned and facing the windshield. When the shot returns to a close-up of her in the car, she is in the same position as when Peter was in the car with her, then she turns to face the windshield and drives away.
Continuity: In a scene at the bar, Peter's drink turns from light pink to dark pink, and back again
Continuity: When Peter is talking to Chuck whilst on the surfboards out at sea, his hair isn't very wet at first, then suddenly is very wet and slicked back - just the same as when he's talking to Aldous in a similar situation later on, showing how those scenes must have been filmed at the same time.
Continuity: During the scene where Peter and Rachel are talking on the cliff, Rachel's shots are shot during a sunny day, while Peter's are when it is overcast. During the shots of Rachel talking, you can see direct sunlight on Peter's left shoulder. During shots of Peter talking, the sky is overcast, and there is no direct sunlight.
Crew or equipment visible: When Rachel is in the water telling Peter to jump off the cliff, her blue lifebelt is visible under and above the water as she bobs around.
Continuity: (Around 57:30) When Matthew the waiter is doing his English accent when giving his demo to Aldous Snow, Aldous' shirt collar corner alternates between pointing towards his chest and away from his chest. Also the yellow beads and red beads on his necklace alternate positions between shots.
Continuity: When Peter is checking into the luxury hotel and standing behind the newlyweds, the bride's arm alternates between being wrapped around her husband's waist and around his neck, cupping his ear.
Continuity: When Aldous Snow is leaving the hotel, his female driver can be seen in the background walking to the car twice.
Continuity: When they tell Peter he needs to get out of the suite, he first puts the sheet over his naked body. Towards the end, the sheet is off again.
Continuity: In the scene where Peter meets Kemo on the beach and is given a beer, when the camera is facing Peter from behind Kemo, the bar towel is missing from Kemo's left shoulder. But when the camera is facing Kemo and behind Peter, it is there again. There are 4-5 alternating shots showing this mistake.
Continuity: When Pete is talking to the buffet guy, the hostess towel disappears from his shoulder and then a few seconds later reappears again.
Continuity: When Peter first meets Sarah and Aldous in the hotel lobby in Hawaii, Aldous approaches Sarah from behind and swats her butt with his open right hand. In the next shot he is holding his single flip-flop sandal in that same hand.
Continuity: In a few scenes where Peter is wearing a lei, it changes position and the flowers face the other way in between shots.
Continuity: In the morning restaurant scene where the waiter brings his pineapple/rum drink and an extra rum mini (Malibu rum) the level in the glass goes from about 2/3 to about 1/3 before he picks it up to drink it.
Continuity: In the scene where Brian asks Peter if he is following Sarah and Aldous we see them making out on the patio of a hotel room that is to the right. Later in the movie when Peter ends up in the room that is next to Sarah and Aldous' room, he is in the room on the right and they are now in the room on the left.
Continuity: When the group are in the restaurant and Sarah says that the movie they are discussing was the right choice for her at the time she downs her wine. The shot then cuts to Peter and Rachel, and the wine bottle is visible throughout. When the shot pans back to Sarah her wine glass is half-full again.
Continuity: When Peter is told he has to leave the first hotel room because Dakota Fanning needs it, he is laying in bed, and the blankets that cover him up switch from off to on to off again.
Continuity: In the scene where Peter is following Sarah and Aldous (while talking to Brian on the phone), they break off and go on a dock, seconds later they are seen making out just outside their room.
Continuity: In the scene where Mathew the waiter is giving his demo to Aldous Snow, the cake and several napkins on the tray he brought disappear by the end of the scene.
Errors in geography: In the scene where Peter is helping to carry the pig on a pole to the luau, the characters walk along the beach against a background that includes the sun sinking into the ocean. This is a physical impossibility, since they're on the North Shore. The sunrise is visible from this location, but the sunsets are only visible from the opposite (south) side of Oahu.