Hundreds of hipsters in Williamsburg, Brooklyn, are gearing up to watch a rented groundhog whisper in the ear of ex-mayoral candidate Curtis Sliwa in McCarren Park on Saturday to see whether they'll be getting six more weeks of winter. The loopy local twist ahead of Feb. 2, Groundhog Day's official date, is the brainchild of 26-year-old event organizer Riley Callanan - who shelled out $2,250 to rent the varmint from an animal rental service.