Project Ginger: It's hailed as a life-changing invention. But what is it?

Dean Kamen is hardly your run-of-the-mill type. He lives in a hexagonal house; he is an aviation enthusiast who commutes by helicopter; he dropped out of college aged 20, and says he holds the world record for the longest uninterrupted period wearing denim - he is never seen without a trademark denim shirt.

Dean Kamen is hardly your run-of-the-mill type. He lives in a hexagonal house; he is an aviation enthusiast who commutes by helicopter; he dropped out of college aged 20, and says he holds the world record for the longest uninterrupted period wearing denim - he is never seen without a trademark denim shirt.

He is also a multi-millionaire, who rubs shoulders with the glitterati including the US president-elect, George W Bush (though he was once seated beside the actress Shirley Maclaine and the actor Warren Beatty, and had no idea who either was).

He has made his money through his inventions, and some top minds who have seen his latest one say it could completely change the way that we live - bigger than the internet, as important as the PC, and so fundamental it will alter the way that cities are designed.

"IT" - or "Project Ginger", as it is also being called - remains a closely guarded secret, however. Nobody, outside a tightly knit group which includes the billionaires Steve Jobs, head of Apple Computer, and Jeff Bezos, founder and head of Amazon.com, as well as the venture capitalist John Doerr, plus a few engineers in Mr Kamen's company DEKA Research, knows what IT actually is.

But that has not stopped a spiral of excitement surrounding the product. For a technology industry that has seen the internet bubble burst, and demand for computers slump amid whispers of a US recession, a new technology wonder is exactly what was needed.

The buzz is almost palpable. The Harvard Business Press has signed a book deal for $250,000 (£166,000) with Steve Kemper, a journalist who has had exclusive access to the development of "Ginger" - but it does not know what it is either. The few details that have slipped out about the prospective product, via Mr Kemper's proposal, have only served to whet appetites - and set the internet abuzz.

According to Mr Kemper, Mr Jobs and Mr Bezos attended a demonstration of "Ginger" - in fact two of them. From a few cardboard boxes and a couple of large duffel bags, Mr Kamen assembled two of them using a screwdriver and hex wrenches in just 10 minutes.

Mr Jobs's reaction is quoted as: "If enough people see the machine you won't have to convince them to architect cities around it. It'll just happen." According to the book proposal, Mr Bezos laughed when he first saw IT - and then added: "You'll have no problem selling it. The question is, are people going to be allowed to use it?" The price, it appears, will be about $2,000 (£1,300).

Mr Kamen told Mr Kemper that his invention will "profoundly affect our environment and the way people live worldwide. It will be an alternative to products that are dirty, expensive, sometimes dangerous and often frustrating, especially for people in the cities." He added that it will "sweep over the world and change lives, cities and ways of thinking".

If all this has you in an agony of anticipation, it is not going to end now. Yesterday, Mr Kamen's company DEKA, based in Manchester, New Hampshire, was issuing a brief statement that "while projects are in their development phase and have client confidentiality requirements, it is impossible for us to comment further".

Asked if the company had filed new patents on "Ginger", Donna Tamzarian, for DEKA, replied: "I can't say." Asked if it had been mentioned, even peripherally, in previous coverage of DEKA or Mr Kamen, she said: "I can't comment."

The hype is enormous, and it looks unlikely that the secrecy around the product, which also has investment from the merchant bank Credit Suisse First Boston, can survive to next year, when Mr Kamen says "Ginger" will be unveiled.

Yet it would be foolish to put anything past him. In 1976, aged 25 and in his third year at Worcester Polytechnic Institute in the US, he got chatting to his brother, then a medical student, who noted how there was no means to give people a steady flow of medication. Mr Kamen turned his mind to it - and dropped out to form his first corporation. In 1978 he demonstrated the first portable infusion pump able to dispense insulin, and other drugs, allowing patients to get out of hospital despite needing round-the-clock medication. In 1982 he sold the product rights, making him an instant multi-millionaire.

The money from that enormously useful device, now used around the world, let him set up a hands-on science museum for children and FIRST - "For Inspiration and Recognition of Science and Technology" - which holds an annual technology contest for American schoolchildren.

In 1993 he developed his second winner, a portable dialysis machine weighing just 10kg (22lb); it won design awards and he was awarded the Hoover Medal, given for "inventions that have advanced medical care worldwide". In 1995, he unveiled a robot wheelchair, the iBot, which can climb stairs.

Now aged 49, Mr Kamen is (in Mr Kemper's words) a combination of Thomas Edison and Henry Ford, a "true eccentric, cantankerous and opinionated, a great character". He is also terrified that if word gets out about what IT really is, then big corporations will "use their massive resources to erect obstacles against us, or worse, simply appropriate the technology".

That fear makes him just like any other successful inventor - and many failed ones. Certainly Trevor Baylis, the British inventor of the clockwork radio, is familiar with the paranoia of creation: "These days, your intellectual property is the most valuable thing you have. These days, the biggest heist you could pull wouldn't be robbing a bank - it would be something like stealing the formula for Viagra, or its successor. He's got to be prepared to defend his product."

That of course depends on its status. IT is not medical. And the reaction of the billionaires' club suggests that it is something either related to transport or pollution.

What, then? A clue may lie in an article published in Wired magazine last September. It described efforts by Mr Kamen to develop a non-polluting engine, based around the Stirling engine - a design from the 19th century - which could run a power generator, and with it a water purifier. "It can burn any fuel, and you can do all kinds of things with it," Mr Kamen said then.

But he also told Wired that another project, to be unveiled "in the next year", would require building "the largest company in New Hampshire". It would be a consumer device unrelated to health care, and require $100m start-up finance.

Perhaps then, IT is not, after all, the water purifier which millions of people throughout the world so badly need. No clues at all were emerging from DEKA yesterday. "The phones have been really busy," said Ms Tamzarian. More than usual? "Oh yes," she said. "Well, this is New Hampshire."