Going up was fine. It was when we stopped at the top of Liftoff, a 150-foot-tall open-air elevator of sorts that resembles a space-age hot-air balloon, that the nerves set in. "Don't look down," I told myself. That was the easy part. The twinkling neon and bright lights of Las Vegas had me fixated. Sure, my seat had nothing but a waist belt to secure me. The unusually windy evening whipped my ...