Like riding horses? Hate terrorists? Well, now's your chance to trot ol' Trigger around the trail and keep a lookout for Osama at the same time. The Houston Airport System's Airport Rangers are volunteers who patrol the 34 miles of perimeter fencing around Intercontinental. You have to pass a background check, of course. "It's not just Joe Blow coming in," says airport spokesperson Ernest DeSoto. "You have to be badged." The airport system has set up 25 miles of trails with water stops and porta-potties, but those hankerin' for more rugged country are welcome to veer off the paths, DeSoto says. If a ranger sees anyone unusual (vagrant, poacher, dude with a rocket-launcher) he or she must report it to airport authorities. Otherwise, feel free to ride around from sunrise to sunset, seven days a week.