Arts groups in New York have begun to despair of ever being granted their promised role at a rebuilt Ground Zero, but one Manhattan theatre company isn’t waiting for the politicians to nix their contribution. “An experimental multimedia and theater company, 3-Legged Dog was located at Fiterman Hall, next to 7 World Trade Center, before the 9/11 attack destroyed its space.” This week, the company opened “the new 3LD Art and Technology Center, a 12,500-square-foot warren of theaters and offices,” just down the block from its old space.