The Flatiron/23rd Street Partnership will present the Ugliest Sweater in NYC Challenge, which asks New Yorkers to don their most hideous or humorous holiday sweaters and walk the catwalk for a chance to win a weekend in the Flatiron District. The gift package includes a two-night stay at the Mave Hotel, as well as $100 gift cards to O’Live Organic Spa and Green Square Tavern. The event will be held in the public plaza located at Fifth Avenue and East 23rd Street, and contestants can sign up as early as 10 a.m.