Karsten Kramarczik, a magazine art director from Schriesheim, Germany, never liked to fly. Even as a child, he found that the prospect of enclosing himself in a long metal tube and hurtling through the ether at nearly the speed of sound made him shiver. Nevertheless, for much of his life Kramarczik forced himself to get on airplanes. Then, four years ago, doubt mysteriously turned into full-blown panic on a trip to Barcelona. He has not flown since.