Before donning a flight suit, customers of Flyaway Indoor Skydiving in Las Vegas sign a waiver that warns, "You can be seriously injured or even killed." For $35 you get a thrilling but strenuous three-minute flight in a vertical wind tunnel on a 120-mph column of air created by a DC-3 propeller driven by a 1,000-horsepower engine. Outfitted with elbow pads, a baggy jumpsuit, earplugs, goggles and helmet, you lie on the wire-mesh floor and wait for the wind's lift, then extend perpendicular to the airflow with chin up, arms and legs forming an X, toes pointed, knees bent slightly. And, oh, yeah, you can be seriously injured or even killed (though no one has bought the farm, so far). Don't forget to smile.