It's Thanksgiving break at exclusive Waverly Academy, and everybody's feeling thankful . . . for the long weekend. New BFFs Jenny Humphrey and Tinsley Carmichael are determined to snap their glum but still uberstylish roomie Callie Vernon out of her funk-it's been weeks since her boyfriend Easy Walsh was kicked out of school, and they're sick of her moping. The plan: head to NYC for some R & R And some SS (serious shopping). But the girls quickly...