PETER COPPOLA SALON AND SPA in Westport, CT, offers clients a healthy and naturally straight hairstyle with its ever-popular Keratin Complex Hair Therapy service. The stylist first clarifies the hair before applying a keratin-infused protein solution, then carefully goes over small sections with a flat iron to seal the straightening effect. The process, which takes just two hours, removes 95 percent of frizz and curl, and the results last from three to six months. And unlike its Brazilian or Japanese competitors, Coppola's straightening service doesn't permanently change the structure of the hair and is free of damaging formaldehyde. —G.B.