Between holiday shopping, parties, concerts and gift wrapping, make room for one more task: whittling down your 2011 tax bill. A number of smart moves can save a bundle in taxes, but you’ll have to act quickly. Just about all of these maneuvers come with a year-end deadline. “You don’t want to realize next April that you could have saved yourself money if you had only focused before the end of the year,” says Neil Becourtney, a partner at the tax advisory firm J.H.