This week, Disney star Selena Gomez joins "Gossip" gals Leighton Meester and Katie Cassidy in Fox's "Monte Carlo." Gomez plays two roles -- a middle-class Texan on vacation with her friends in Europe and a European heiress -- in the "princess and the pauper"-esque film. It's not getting great reviews, with the Post's Sara Stewart calling it "earnest and predictable," but Gomez has already proven herself to be a box-office moneymaker. Last summer, she helped Fox's well-reviewed "Ramona and Beezus" rake in $27 million worldwide, almost double its $15 million budget.