Saying regulators are stifling innovation, the National Association of Realtors and nearly three dozen other groups have sent a letter to the Federal Aviation Administration urging the agency to speed up its process for issuing rules that will govern the commercial use of drones. The groups, which also include NAR affiliate Realtors Land Institute, also urged the FAA to allow limited use of small drones for commercial purposes right away, before a final rule is complete. "The current regulatory void has left American entrepreneurs and others either sitting on the sidelines or operating in the absence of appropriate safety guidelines," the letter said. "The technology is advancing faster than the regulations to govern it." Drones have gained popularity in real estate in the past ...