Alicia Silverstone hit it big updating Jane Austen's Emma to high school in Clueless. Easy A, a teen comedy loaded with killer laughs, does the same trick with Nathaniel Hawthorne's The Scarlet Letter. Director Will Gluck plugs in live wire Emma Stone (Zombieland) as Olive, a good girl faking it as an easy lay to . . . ah, just see the movie. The jokes are hit-and-miss. But Stone is one sassy babe and a breakout star who nails every zinger and brings genuine warmth to her scenes with her parents, played by the priceless Patricia Clarkson and Stanley Tucci. You mean girls can eat it.