There are many ways, I suppose, to make your first million, but lone inventor, 62-year-old Trevor Baylis cracked it with the first successful prototype of a clockwork radio. It's almost a romantic idea - attempted by Marconi at the turn of the century, and even in the 1950s - but nowadays components are far more energy-efficient than the old valve radios.
Baylis is an interesting old cheese; a cheery, unsentimental, philosophical, Cockney geyser who, once relaxed, is happy to spray out unprintable remarks in the 'Arry Palmer wide boy accent.
I met him after his stint on RTE's mid-afternoon programme, Open House, when he discomfited Marty Whelan by smoking his pipe while touting his book, Clock This. Dedicated to a long list of girlfriends down the years, it's a hard-boiled and often very funny autobiography.
Although Baylis is a refreshingly unreconstructed ladies' man, it delivers some of the same surprise I remember from first reading Quentin Crisp. A former stuntman, circusman, underwater escapologist, swimming pool salesman and British army lance-corporal in Northern Ireland in the very early 1960s, Baylis traces his only-child origins fondly from his north London family - and the punch of early sexual abuse at the hands of a Catholic priest.
From his first Meccano set, found among the rubble of second World War London, he built his first engine at the age of 13, with his dad's help. Later, he claims, as a swimming pool salesman, he built the first automated chlorination system.
But nearly a decade ago, watching a Panorama Special on the spread of AIDS in Africa, he learnt that basis safe-sex education projects were being fatally hampered by the lack of affordable batteries, to power radios in remote regions where tens of millions of people live without electricity. It sent Baylis to his workshop, filching components from radios, dynamos, even a constant force spring from a car seat belt. After much trial and error, he built a robust little machine which played for 14 minutes.
He approached countless multinationals, and even the British Design Council, but all turned him down rather snootily. Finally, with nothing to lose, he appeared on BBC's Tomorrow's World in 1994. Amid the deluge of congratulatory phone calls came a fax from a Christopher Staines: "a corporate accountant, a mergers and acquisitions type, the last person on Earth I would have expected to have an interest in a clockwork radio."
At the time, he was "financially exhausted", having already had a rough experience with his "Orange Aid sets" - an eccentric but effective contraption of little inventions aimed at enhancing the lives of disabled people: one-handed peelers, slicers, nail-cutters, foot-operated scissors, even a gizmo to help somebody smoke a cigarette.
Although the kits were successfully brought to market, the company went belly-up and Baylis lost at least £20,000. "I was kippered up by the sharks who moved in on me, manipulating their A shares and B shares. The most dangerous combination of all is a lawyer and an accountant.
"As an inventor, you come up against a couple of those skills, mate, and you're in real trouble. Most of us just do what instinct tells us, which can often be wildly wrong, because we're surrounded by spivs, crooks and vulture capitalists. Guys with posh voices and big suits aren't necessarily people to trust."
However, with Staines and other investors behind his "Freeplay" radios, Baylis hit paydirt. The four big BayGen manufacturing plants in Cape Town are now thumping out 120,000 radios a month; with a mixed-race workforce spread between able-bodied and disabled people. General Electric also bought a third of the company, ploughing technical expertise and components into making the sets more efficient.
There are now a number of models, in tough see-through plastic, the smallest one also sporting a solar panel and a storage system, which can deliver 15 hours of radioplay from a 30-second wind.
Other products are coming: a clockwork torch, a satellite navigational device, even a way of running a cellphone out the back of the torch. "Which means if you're in a Mayday situation, you've enough power to make a couple of phone calls - as often as you want to wind that handle."
At a trade fair in Botswana, Baylis even got an Apple E-mate laptop and "joined it up in holy communion" with one of his clockwork generators, and got the first ever 16 minutes of clockwork activity from a computer before it crashed.
Apart from winning Baylis an OBE, the BBC Design Award, a Presidential Gold Medal from the Institute of Mechanical Engineers ("these honorary doctorates and professorships come through the post now"), he's also the current Pipe Smoker of the Year. "Obviously, people in the trade watch the television - it's one of those strange things that a pipe can be allowed on a show, whereas you couldn't put a cigarette on. It's weird, it's still socially acceptable for some reason."
Nowadays, the US is the largest market for the radios, then Europe, Africa and the Third World, where aid agencies bring them in (47,000 Freeplay radios went into Kosovo).
"Whenever you've got an earthquake or a flare-up somewhere," says Baylis, "the UN or UNESCO put the radios in strategic places, so that people know where the field stations are, the medical boys, fresh water . . ."
Interestingly, he understates his altruism: "You mustn't look upon me as some holy roller. My need wasn't primarily driven by those poor souls in Africa, but by my passion to make the bloody thing work - there's a difference. The important thing to realise is that you've got to eat first, so you're capable of helping other people afterwards."
He does talk happily about the humanitarian spin-offs of his invention, but also - angrily - of "scores of great British inventors who died in poverty, all the way back to Roger Bacon. Look at poor Chistopher Cockerell, whose dying words were `it would have been nice to buy my wife a meal now and again' - and he invented the hovercraft!"
Which gets him onto his current project. "I want to get an academy off the ground, a place where inventors can safely go. We sign a confidentiality agreement if we think your idea is good news, and we do all the work that you can't do - on the understanding that we can share in your success. Then we'll sell your product on to the highest bidder . . .
"It won't be a teaching academy as such, it will be more a hands-on, let's-help-you type academy. There's an invention in everyone, but nobody pays you for a good idea. You have to have a prototype, a working machine no matter how crude, that makes the statement.
"And you have to do a patent search, to find out if it's been done before. Ignorance is no excuse, if you file a patent for something someone has already done, they could sue you from arsehole to breakfast time. But patenting laws are just a part of it. None of us have got all the skills, or the money, to bring a product to the marketplace."
He happily admits the radio has brought him "a quality of life I never thought I'd have. We're not talking cash now - I've always lived well, the friends that I keep, the house I built myself 30 years ago on a delightful island in the Thames - it's on the ancient Eel Pie sandspit, off Twickenham with the indoor swimming pool, the hot tub, the boat . . .
"And the value of the company is going up day by day, my shares are worth about four and a half million dollars, and I've just sold my intellectual property in it for 1.3 million dollars, and I'm taking in 800,000 dollars over the next five years. So, as long as I've got a hole in my arse, I should be able to survive quite nicely, thank you."
He never married. "I'm on the shelf between a couple of delightful book-ends, if you get my drift," he grins, pulling a picture of his two lady-friends from his briefcase.
You're eh, going out with both of them? "Well, not at the same time, it can't be done," he chortles, winding me up like a Freeplay radio.
But do they not get, eh, jealous? "No, they're a couple of good pals. It suits them and it suits me."
Does he regret not having children? "Yes, but what you've never had, you can't grieve about. And the kids could have grown up and ended up doing bird. You just can't tell how they're going to turn out, can you?"