When the girls, Adam, and Marcus split up on the ATV's after finding that Max is following them, we see that Marcus is the one driving the boys' ATV, but later on, we catch a glimpse of Adam driving it.
When the Aztecs get their first reward, they show clips in the club. You see Charles dancing with Lizzie and Shane who are both on a punishment and not supposed to be in that scene.
At the beginning of the film, Shane lives in California with her dad. When she is talking to Adam later in the film, she says she moved to California with her mom.
Near the end of the movie, when the two teams are competing in a relay race, they have to swim in a pool then race on wave runners in the ocean. A few minutes later, when you see the teams racing on the beach to the rope ladders, everyone's clothes are dry. There is no way their clothes would have dried in that time.
Some eyeglasses (for nearsightedness) can be used to make a fire in the method shown in the film, but only in the orientation opposite that of the one they use.
During the end flashback sequence, the shot of Kylie and Taylor's wet birthday cake from Getting There (2002) is flipped: the "SWEET 16" banner is reversed.