(FORTUNE Magazine) – People don't have ideas, ideas have people, according to a currently fashionable evolutionary view of culture. Ideas, like tunes and styles of dress, are snippets of cultural genetic material--inhabiting our heads, mutating, replicating themselves in the media--and the strongest of them drive out the weak. In addition to being seductive, the concept is a handy way to think about the deep changes under way in the economy: digitization, information technology, the explosion of deregulated communications. Since Oxford zoologist Richard Dawkins proposed this viral theory 19 years ago, much has been written about it.

And practically every word that has been written about it has been produced by people using a device so deeply boneheaded, so inescapable, so tragicomically flawed, that it makes a rational person want to run screaming into the woods: the standard typewriter (and computer) keyboard. The qwerty keyboard, a central artifact of the information economy, was arranged in the 1870s with a deliberately awkward pattern of letters to slow typists down so they wouldn't jam the innards of early typing machines. Billions of dollars of lost productivity, and possibly an epidemic of repetitive stress disorders, have been the result. Alternative arrangements of keys have proved to be as efficient, and as successful, as Esperanto. The bad keyboard is an idea that has won, an immovable oddity. Perhaps the stern test of the marketplace produces results more capricious than we like to think.

That conclusion is a tempting one to draw from the pages that follow, in which Fortune surveys the ideas that have met this test and propelled a fortunate few up the 500 list. Who would have thought that Sam Walton could prosper by turning his back on suburbs as they boomed? That Nike could make a killing without actually making shoes? Conversely, why did it take the facsimile machine more than a full century to catch on as a business tool? And why did global marketing fall on its face in an age of global shrinkage?

In these essays, Fortune writers examine those and other results of the great contests of the imagination for which the 500 list serves as scorecard. Many of their conclusions are counterintuitive, and yet there are practical lessons here. Innovations in corporate finance have produced one in- jury after another, but that is because the sharpest tools demand the most care in handling. Technology is indeed a business of invention, but inventing, it turns out, is the easy part. Managing scarcely existed as a discipline when the Fortune 500 list was first published, and if it seems at times like a field whose practitioners are forever dreaming up new names for old behavior patterns, it has produced broad insights that genuinely create value. Marketing may be the most mysterious of the disciplines examined here, involving the manipulation of ineffable emotions, but here, too, the past 40 years hold lessons--particularly about the peril of getting trapped in the mass market.

The ideas surveyed here are not deemed good or bad--just effective, as measured by the hard judgment of the marketplace. Understanding the things that link them will, we hope, provide a useful lens through which to view an economy undergoing its deepest, swiftest changes in generations. The communications revolution is opening new markets, and even new kinds of markets, every day--witness the anxious anticipation that surrounds the Internet. The pace at which ideas can create--or destroy--wealth has increased exponentially. What will the next big one be?

Me, I'm rooting for voice-recognition technology. That way, when we publish the Fortune 500's 50th anniversary issue, we won't have to do it using these damned keyboards.

- Timothy K. Smith