This is Populazzi by Elise Allen (Who pretty much co-wrote Hilary Duff's novels). It just came out Aug 1/2011 but I haven't gotten it yet, I so want to though! I love the cover, and the story sounds pretty good.
WHAT WOULD YOU DO if you had the chance to erase your past and reinvent yourself as the person you’ve always wanted to be? Would you grab it? Would you stick with it, no matter what the consequences?
Cara Leonard always wished she could be one of those girls: confident, self-possessed, and never at a loss for the perfect thing to say. One of the Populazzi.
It always seemed impossible… but now could be her chance.
When Cara moves to a new school just before junior year, her best friend urges her to seize the opportunity and change her life… with the help of The Ladder. Its rungs are relationships, and if Cara transforms herself into the perfect girlfriend for guys higher and higher on the Popularity Tower, she can reach the ultimate goal: Supreme Populazzi, the most popular girl in school.
The Ladder seems like a lighthearted social experiment — a straight climb up — but it quickly becomes gnarled and twisted. And when everything goes wrong, only the most audacious act Cara can think of has a chance of setting things even a little bit right.