With PowerPoint presentations, Palm Pilot-beaming executives and cell phones trilling in the audience, last November’s e-Book World seemed typical of the hundreds of business-tech gatherings held every year. But it wasn’t. In fact, it was the first conference devoted solely to the forthcoming transformation of the book world by digital technology. Hundreds of people from around the world paid as much as $995 to hear some of the most influential editors and publishers in the United States forecast radical changes in the writing, distribution and reading of printed material.

The new e-books were on display in the exhibit space. They were, for the most part, keyboardless computers, each about the size of a paperback. Visitors gingerly tapped the screen or thumbed a button to “turn” the pages on these gray boxes; with some models, readers could “bookmark” favorite passages. Don’t be fooled by their unprepossessing appearance, conference organizer and author Michael Wolff warned in his keynote speech. “The e-book,” he proclaimed, “is the most significant development in the book business since the advent of the paperback.”

Maybe. Digital technology and books, magazines and newspapers are certainly going to collide, just as Wolff said. And, as he also said, the results will have an enormous social and cultural impact. But the key invention will not be the electronic book-at least not the gray boxes on exhibit at e-Book World. Instead, it will be a development that not a single speaker at the conference addressed-a product that not one of the companies in the exhibit displayed. Although the collective imagination of the publishing industry has been captured by the current generation of electronic books, the technology that is most likely to transform reading and writing will be electronic paper.

A handful of leading technology companies are vying to create the first practical electronic paper-a digital display thin and flexible enough to roll into a tube or fold up like a map, yet cheap enough to be sold in reams or wired with a few hundred other screens into the spine of a notebook. Recent progress has been so rapid some researchers believe that in just a few years this novel kind of display could replace paper in many situations, leading to the creation of books, magazines and newspapers made from sheets of wired plastic.

“We’re talking about something that would be the first real change to the technology of the book in 500 years,” says Paul Drzaic, technology director at E Ink, a startup in Cambridge, MA that unveiled an initial prototype of e-paper late last year. “You have to be aware of the implications. We’re not comparing ourselves to Gutenberg in any way, but it’s incredible to think that we could be in a time that would be mentioned in the same breath.”

Historians have long argued that the technology needed to create a printing press with movable type had been in Europe for more than a century before the 1440s, when Johann Gutenberg and several other craftsmen in the German city of Mainz set up the first composing rooms. “But the important thing was missing,” historians Lucien Febvre and Henri-Jean Martin wrote in The Coming of the Book, a classic account from 1958. “It would have been impossible to invent printing had it not been for the impetus given by paper, which [only] came into general use by the late 14th century.”