The purpose of this book is not to serve as some Utopian blueprint, laboriously detailing each nut and bolt of the Living Garden, but to provide the means to sketch an outline of how various ideas, philosophies, principles and technologies could be brought together within an `architectural' scheme. Even so, although this is not a textbook about the technology of the Garden, could such a scheme ever be realised outside the pages of a book, or is it merely a fantasy - or garden folie?

Having already asked the reader to pull on a metaphorical pair of green Wellington boots to wander through the Garden's landscape of ideas, anyone who prefers not to have to don the computer Geek's anorak, too, may skip this short technological diversion. It may, however, come as a surprise to discover that not only does a great deal of the theoretical technology required already exist, but that much of it is relatively simple.

The Key to the Garden

Take the Key, for example, which copies the serial number of a specific Living Book stored on the database. This is not dissimilar to Datatag - a security system already on sale in the United Kingdom. Datatag is based around a passive semiconductor device that `remembers' a unique serial number, and which is small enough to be hidden within items of property. The Datatag kit includes a form which the purchaser completes by filling-in their details of their name and address. The company which administers the scheme then enters these details - along with the relevant Datatag serial number - onto a database. In doing so, an implicit link is established between a (uniquely numbered) tag, an item of property and an individual (the purchaser of a Datatag). Police forces now routinely scan stolen items of property which they recover using special Datatag hand-held detectors. The radio waves sent out by this detector excite any tag hidden within a piece of property, triggering it to emit a low-power radio signal which can be registered by the hand-held detector. The tag does not need any kind of power source as the semiconductor `naturally' converts the energy of the incident radio waves to emit its own signal. This signal contains the tag's unique serial number which is picked up, decoded and displayed on the detector. All that is required is for this number to be checked against the Datatag database to find the name and address of the original property owner. Datatags are small, light and cheap enough to be fitted to virtually any object. Clearly, the Garden's Key works on similar principles, except that each Key identifies a Living Book (rather than an owner's name and address) and all the detection, search and retrieval processes are automated.

Olivetti Research in Cambridge has also just launched the Active Badge which uses infra red signals to constantly keeps tabs on the position of Active Badge wearers (people and objects) within an office environment. The system can constantly update a computerised map of the location of all badge wearing staff (or stapling machines) within a building1. This commercial implementation certainly has `Big Brother' overtones, but the Garden offers an illustration of how one set of technologies can be used to affect very different ends. Within the Garden, technology similar to that developed by Olivetti would provide the means to locate the position of a Keyholder, generate maps and guide visitors to any garden location.

Materially, the Key might look something like a small coin, a pill, or postage stamp - a size and shape (like a miniature version of a cash card) which would be designed to fit into the standardised `keyhole' of any type of authoring tool. Once a blank Key had been used (thereby storing the serial number of a Living Book), an author might decide to secrete the Key within an object - a ring, brooch, a photograph, for example - something which may confer a physical identity on the Key/message as an artefact, before it is passed on to its recipient. A Key could even be inserted into a human body, or perhaps place in (or recorded onto) a piece of fruit: if a message is not retrieved before the fruit rots away it will be lost forever - perhaps a means for signalling the urgency or need for a rapid or immediate dialogue?