Mayor Bloomberg has selected Lady Gaga as his special guest on New Year’s Eve to push a Waterford Crystal button and drop the ball in Times Square at 11:59 p.m. Each year, Hizzoner chooses a guest to help drop the ball and count down the year’s final minute. Past choices have included Bill and Hillary Clinton, Colin Powell, Muhammad Ali and Rudy Giuliani. Lady Gaga will perform on ABC’s “Dick Clark’s New Year’s Rockin’ Eve With Ryan Seacrest 2012.”