Radio's got a problem. Although some 200 million people tune in each week to hear their favorite overcaffeinated DJ or catch those crucial rush-hour traffic updates, it's getting tougher to hold listeners' attention. Facing flat revenues and competition ranging from iPods to music phones, the 87-year-old industry is scrambling to reinvent itself. But not even satellite radio or the new HD format addresses this analog medium's fundamental flaw: it doesn't give people any say in which songs they hear. If you don't like a track or a DJ, your only option is to turn the dial--or turn it off.
That...