About ten years ago, Denver psychiatrist Thomas Crowley began wondering what it would be like to be buried under an avalanche. He decided it wouldn't be very pleasant, so he started tinkering with ways to survive one. After contemplating and then discarding several plans -- wearing a SCUBA tank while schussing seemed cumbersome -- he hit on the solution one August night while lying in bed. Why not design a device that could draw the air out of snow and then direct exhalations behind you? After several years of testing and perfecting, last year, for the first time, Crowley's invention - which he named the AvaLung -- worked in a real avalanche, saving a backcountry skier.