(FORTUNE Magazine) – Deep in the heart of every entrepreneur lies the secret and ever so slightly subversive desire to change the world. Not necessarily to stand reality on its head, but to take that one eureka! moment and turn it into a product that inspires people to exclaim "Cool!" or "Neat!" or "Yo, this $#*! is dope!"--or maybe simply stare at what you've done in grateful awe, the way you did when you first hit "run" and the thing actually did.

The entrepreneurs on the following pages are leading 12 companies we think have a pretty good shot of getting people to say "cool!"--and in the process, permanently alter the world as we know it. If freaked-out twentysomethings Barrett Comiskey and J.D. Albert of E Ink, for instance, manage to live out their wildest dreams of infiltrating the country with paperless paper, we'll all one day be downloading customized newspapers not to a computer but to some thin thing that actually looks like a newspaper. Brave new world stuff.

Recent history shows that some of this year's fearless technophiles will end up papering their offices with stock certificates that once promised real value (see the preceding story for a review of what happened to FORTUNE's past five years of cool companies.) But none of today's darlings fear failure--or if they do, they're sure not going to let on to us about it.

Paperless paper is just one world-changing possibility you'll find here. Alex Mandl and Buddy Pickle of the well-funded startup Teligent plan to make cheap wireless local phone service ubiquitous. What will become of the scraggly telephone wires scarring the landscape of our cities and suburbs? Where will the birds sit? If Dragon Systems' breakthrough voice-recognition software gets much better, we'll all forget keyboards and be on speaking terms with our PCs. Perhaps this will give rise to a whole new literary category--novel speakers. And because the key to the future proliferation of most tech innovation is the Internet, our list has two companies that aim to make better use of the Net's bandwidth. With products from Aware and eFusion you could, say, use your PC as a phone while simultaneously downloading an encyclopedia at superfast speed.

Do we really need to be able to speak to our computers or have eight million bits of data flooding into our homes every second? That's not the point. The moral imperative for tech tinkering is akin to the response British explorer George Leigh Mallory gave when asked why he wanted to scale Mount Everest. "Because it's there," he said. Our programmers and engineers build new toys and technology because they can. Because they're whip-smart and can't imagine what else they'd be doing if not beavering away 12 hours a day writing software code no one's ever written before or engineering hardware no one's ever cobbled together before. And oh, yeah, because it could make them really, really rich.

--Melanie Warner