Few of us forget our childhood bike. In all its shiny, tasseled, banana-seated glory, it brought us pure joy and our first taste of freedom. Lately, it seems, our collective love affair with bikes is being rekindled, with adults around the country feeling a passion for cycles they haven't experienced since their youth. The objects of their affections? Old-fashioned commuter bikes -- the kind you ride sitting upright, with sleek frames, wide handlebars, and leather handgrips and saddles. Their combination of utility, beauty, and efficiency inspires both design lust and nostalgia.