A living room fireplace doubles as a tool rack at Hanson Robotics, based in a suburban Dallas house where David Hanson lives with his wife and young son. Seven full-time staff members plus an array of part-timers and volunteers come and go seven days a week, often working until 3 a.m. "My wife is supportive," Hanson says, "but sometimes all the activity freaks her out." Here, Kevin Carpenter models hardware in computer 3-D as Katherine Batiste works on Zeno's hair.