In this densely packed deliberation on the shape of things to come, Kelly, the executive editor of Wired, offers a biological paradigm for a whole set of scientific and cultural phenomena: virtual reality, self-controlling robots, animation, nanotechnology, games, even the much ballyhooed ``information superhighway.'' Kelly's main thesis is that biological organization offers a degree of adaptability impossible with the more familiar hierarchic mechanical organization. A swarm of bees has no single guiding intellect; it arrives at a consensus based on the input of various individuals, generating more or less enthusiasm for a proposal as members go out to verify various reports. This lack of central control becomes a model for a variety of processes that combine great freedom of the individual parts with sophisticated overall performance. Computer networks like the Internet are classic examples of anarchy in action, making available an enormous amount of information with a minimum of structure. Space researchers have begun to speculate that a swarm of small, very simple machines independently following very simple instructions may be better able to prepare a lunar landing site than a single, more complex device. The ultimate in simplicity lies in the infant science of nanotechnology, which envisions the use of extremely simple machines no larger than some organic molecules. At the other end of the spectrum, Mark Pauline of San Francisco makes enormous ``organic machines'' out of spare (or stolen) parts and sets them to destroying one another in bizarre exhibitions that resemble freaked-out reenactments of the Roman circus. The book is full of such fascinating characters and oddball insights into the interplay between technology and living forms. Kelly's organization is often as seemingly uncontrolled as some of the processes he discusses. But the book as a whole is rewarding, full of food for thought, and a convincing preview of the probable future of technology.