The Gay and Lesbian Tennis Alliance (GLTA) is the international organization that manages and sanctions the gay tennis circuit around the world. There are 40 gay and lesbian tennis clubs around the world that comprise the GLTA. With over 39 annual GLTA-sanctioned tournaments in the U.S, Canada, and Europe, the GLTA is the fastest growing gay sports organization. An estimated 5,500 players will take part in GLTA tournaments over the next year, and the number of tournaments and players grows each year. The gay athlete. An oxymoron, right? "That's a stereotype," says Gino Lestino of Fort Lauderdale. "Gay athletes can be just as athletic as straight athletes." Lestino, 34, is co-chairman of the third annual Miami Art Deco Open, a tournament next week at the Lipton tennis center in Key Biscayne