You would think Miami's ample public space near the shoreline and constant easterly breeze would make kite flying as popular as Rollerblading on South Beach. Well, maybe not. But some think it's hip to sail the winds with cloth and string. A few of these aviators/eccentrics can be found showing off their kaleidoscopic flights-of-fancy Sundays on the beach at Crandon; some are employees and customers of Sky Dancers, a kite shop in Coconut Grove. Besides sending aloft their rainbow-color wonders, which come in shapes ranging from a parrot to a cube, they are also willing to share a trade secret or two with novices. Some day soon this could become Miami's next big fad, as cool as Rollerblading on South Beach. Okay, maybe not.