Whilst the concept and the advertisement make this movie seem very attractive and comic the film does not live up to expectations. I'm guessing the point of this movie was to see Elizabeth (Diaz) develop as a character and transform from a superficial gold digger to an honest, down-to-earth role model for her students, but I did not see this. There is no development of Elizabeth's character, she seems to just change from one person to another, but even at the end of the movie Elizabeth does not seem like a very good teacher or someone with particularly good morals.
There are some sexual scenes in this movie and they are probably the funniest things about this movie because they're just so god-damn ridiculous. (Yes, Cameron Diaz and Justin Timberlake dry-humping is hilarious.) They scenes don't add anything to the plot at all. In fact, I'm not even sure why they were included seeing as movies about 'bad' teachers should be aimed at children and teenagers who actually attend school and have bad teachers therefore making this movie extremely inappropriate. Watching Diaz throw her wet body at a car just reminded me of a fish out of water, flopping around. Of course, she did look sexy whilst doing it in as little clothing as possible, but still, she looked ridiculous.
I found the plot line very boring throughout the movie, not a lot seemed to happen. The main focus seemed to be on Elizabeth trying to earn money for a boob-job, which she doesn't even get in the end. Supposedly this shows her epic change in character proving that you don't need to change yourself and blahblahblah but it doesn't. Curiously, Scott (Timberlake) agrees that Elizabeth should get a boob job because he believes that it's okay to want to improve yourself; however, I got the impression that he was supposed to be the character with the greatest morals in this movie, so whoever developed his character didn't think that one very well through.
At the end of the movie Elizabeth starts to date Russel (Jason Segel), the gym teacher, this also is presumably to show that she is no-longer a gold digger, but it doesn't. She even asks him if agreeing to go out with him means that she's consciously making the decision to be with a low-paid gym teacher. Their relationship also appears to be mainly sexual as the pair don't really interact that much throughout the film.
All in all this is a movie about a gold-digger who's extremely lazy and bad at teaching, in the end she is not so much of a gold-digger, she's slightly less lazy, and slightly better at teaching, but to be honest, there isn't much of an improvement. Don't bother wasting your money on this movie.