Forget about applying for a patent because you're worried about somebody else stealing your brainchild. Here's the real reason to do it: so you'll know how to get around the patent. That skill came in handy when Horace Furumoto fell out of favor with the board of Candela, the scientific-laser company he'd founded in 1970, and began looking for a new job in 1991. He started Cynosure to compete against Candela with a similar product--a medical laser to remove birthmarks. Although Candela retained the rights to the original laser, "it was my patent, and I knew it inside and out," Furumoto says. Candela wasn't happy and dragged the start-up through two years of costly litigation. "We won on every point," says Furumoto.