Now that the legendary Greenhouse spa has opened its new branch on 57th Street, itís easy to see what lured Elizabeth Taylor and the Duchess of Windsor to the Texas original. After passing through the high-ceilinged lobby filled with goodies like Chantecaille makeup and Belle Fleur bouquets, guests head downstairs, not to a communal locker-room, but to a coat check with private changing areas. The emphasis on privacy extends to the cozy, individual manicure and pedicure banquettes that come with built-in TVs and tabletops so that you can order a seared-tuna salad while your toes are buffed and polished. Those awaiting more extensive pamperingóbe it a bronzing session ($125), soothing hot-stone therapy ($135), or botox injections (they start at $750 for two areas)ócan relax in the sunny second-floor lounge, complete with skylight. And donít worry about the time: A Greenhouse staffer will even walk your dog while the coddling continues.