Goofs

In the sorority car wash scene, Natalie deliberately turns the water hose on her shorts. At first, the wet area is very large and soaked but when the camera cuts away for a fraction of a second and cuts back to her, the wet area shows just a few traces.

When Joanne (Rumer Willis) starts running towards Steve (Tyler Spindel) with her brace on, it breaks off and you can see it behind her. When she finally catches up to Steve the brace it is no longer behind her. Then when it zooms up to Shelly, you cannot see the brace in the direction she's looking.

During the Aztec party, when Natalie steps out of the water following her "sacrifice", she is completely dry.

When Joanne starts running towards Steve her hair is lighter then when she walks back into the camera with Shelly.

When the girls from the Phi Iota Mu Sorority release the pig into the Zeta's house Joanne, Rumer Willis' character, falls off her chair 2 or 3 times without ever been seen getting back onto the chair.

The Zeta Girls' calendar shows June with 31 days.

Playboy Bunnies were waitresses at the Playboy Club chain. Playmates are nude models.

When the Phi Iota Mu girl stole the bids, Lilly can tell the leaders of the Panhellenic meeting that the girl stole them, which would have achieved nothing because she not only didn't actually see it, she had absolutely no proof of it. The leaders of the meeting would not have investigated or even given it a second thought other than to think they were just making excuses for not getting pledges and revoked their charter.

When the girls are singing karaoke, Ashley and Courtney are typing different self-insulting lyrics to trick them into singing them. However, no karaoke system can do this. Generally nobody can type fast enough to provide lyrics on the fly like this, so the lyrics are pre-programmed, like a video or movie (as such many karaoke tracks can be found on YouTube). The lyrics are hard-coded by the karaoke company beforehand. There's no such thing as live lyrics like this.

Lilly was established as the one who never talks at the beginning of the movie. Yet after Shelley says she had lived in the Playboy mansion, Lilly whispers something in Harmony's ear, presumably in her British accent, so the Zetas shouldn't have been surprised that she spoke, and is British. Of course, she usually whispered.

(at around 3 mins) When Shelly is getting her hair done before her party it is clear that the person actually doing her hair is using some form of straighteners/curlers but isn't touching her hair.

Everybody acts surprised when Lily speaks, especially because she's British but earlier in the film she whispers in Harmony's ear, no one acts surprised when this happens, meaning that she often whispers to people so they should already know she speaks with an English accent.

Shelley's hairstyle changes between her leaving for her second date with Oliver to her being at the restaurant with him. It starts as a twist with a bun, then becomes a regular bun.

When Shelley is washing the car and she talks to Oliver about his job, you can see a crew member on the glass window of the car.

During Shelley's speech before the council to recruit pledges for ZETA, she turns toward the ZETA's and Mona gives her a thumbs up. At that moment a microphone can be seen at the top/left of the screen.

During dinner, Shelly mentioned her butt to Oliver several times and even mentioned that she didn't have any tan lines. However when Shelly was walking around the house naked earlier in the movie, tan lines were definitely visible.

Shelley turned 27 in 2008. Meaning she was born in 1981. But at the beginning, when it showed old pictures of Shelley. There's a picture of her on a teeter totter when she was little. Below the picture, it said the picture was taken in the summer of 1984. In that picture, Shelley looked around 10 years old. If Shelley turned 27 in 2008. She would've been 3 years old in 1984.

Right near the end of the film, when the house girls are discussing Shelly, while removing their makeup at the makeup table, Rumor Willis [Joanne], looks up into camera just as she goes off the left of the frame.