The Sundance Institute-sponsored United States Film Festival has kicked off in Park City, Utah, and Sundance founder Robert Redford says ticket sales are up 30-40% from last year. Since Sundance took over the 10-day fest three years ago, nearly 1,500 people from outside Utah bought ticket packages, compared to 80 two years ago. "We're at the point now where this it. This is the first year we've put a ceiling on the number of outside visitors," Redford said. The festival has become an increasingly popular venue for independent film makers to showcase their films.