Connectivity has yet again despoiled once sacred ground, though this time it's in the air. Whether you're en route to London, Paris or Dubai, a fellow traveler's gritty life details, from stock picks to sex, will soon be audible—or as many view it, inescapable. With the number of flyers growing 6% annually and 3 billion cell-phone devices in operation, foreign airlines are racing to offer passengers the ability to call, text and e-mail with their mobiles and PDAs at about the same rates as for roaming international calls. In the U.S., voice won't be available anytime soon, but wi-fi will make...