There are many books that address the way computers should be used--shelves are full of how-tos that teach everything from designing a Web page to avoiding identity theft. But it is the rare author that looks beyond the current tangle of technology and thinks about the way computers should be designed and, more important, how we ought to use them.

In his forward-thinking riff on computing, Ben Shneiderman claims Leonardo da Vinci as an inspirational muse, positing that if the artist were to suddenly reappear and be given a PC, he might have some fascinating ideas about applications, community, and innovation. By using da Vinci as an example of creative thinking, Shneiderman shows that we, as a computing tribe, have something akin to tunnel vision when it comes to usability. We've lowered our expectations for what technology can provide for us, the author believes, and it shows.

Shneiderman is adept at gently driving home his point, and at laying out a vision of how technology should improve. Imagine, he says with passion and vigor, a World Wide Med that contains patient histories in local languages, that allows doctors around the world to compare notes and call for advice. Other initiatives could connect governments, citizens, and businesses, making us not just a global village but also a unified planet.

It's easy, and quite refreshing, to get caught up in the author's techno-Utopian vision of a world hotwired to serve its populace. There are several moments when it would be nice to have Shneiderman's wishes simply made true, with technological hurdles jumped and cultural boundaries erased. But perhaps for now, without a new da Vinci, it will have to suffice to see such a blueprint unrolled, and think about what could be built from it.