If your answers are mostly C: congratulations, citizen of the wired world, tomorrow belongs to you. If mostly B: well done, keep re-skilling and you'll be OK. If mostly A: oh dear. You're one of those primitive life forms who, in the words of Douglas Adams, still thinks digital watches are a neat idea. Maybe you even listened to the original Hitchhiker's Guide to the Galaxy on your transistor radio, because this level of technological incompetence just doesn't occur in people under the age of 50.

There are even more computer illiterate senior citizens in Britain than there are functionally illiterate schoolleavers, and they are just as excluded from mainstream society. In the past ten years internet use has revolutionised our lives to such an extent that it is now a serious disability to be unable to use the technology.

Most companies do more business by having a website and online ordering. Those with an intranet and video conferencing can cut costs..

In private life, taking photographs, listening to music, keeping in touch with friends, house-hunting, booking holidays, shopping, sending flowers, finding your sweetheart, being a hypochondriac, checking your bank balance and bargain hunting have all become web-based activities.

Since all these things are done more easily, more cheaply and better online, the trend is growing at a dizzying rate. Visa International reported a rise in e-commerce sales of 56 per cent last year. The predictions are for greater internet dominance, pushing people who can't or won't use computers farther into disadvantage.

Overall, 55 per cent of Britons use the internet. The majority of under- fifties do, having either learnt at school or been trained at work. Age Concern estimates that 40 per cent of 50 to 60-year-olds are computer literate. Beyond 60, however, only 12 per cent can use the internet, which means that the web revolution has started without 88 per cent of the people who may need it the most.

For many over-fifties, computer illiteracy has been a fast-track to career suicide. “He wouldn't even have a terminal on his desk,” said a creative industry MD, justifying his relief at sending a technophobic colleague into early retirement. Down the salary scale, many senior shop assistants panicked about using an electronic till and found themselves redundant.

In business, or the voluntary sector, the dinosaur CEO is still common and costly. As trustee of a small charity, I was horrified as the results of half our first year's fundraising were taken by the salary of the chairman's PA. Her main task was to print out his e-mails and type his replies.

Senior technophobes have many excuses, though none quite like Jack Nicholson's: “I had to get rid of the internet; there was so much porn on it I'd never get out of the house.”

Here are some the less provocative favourites. First, the gender cards, as in: “My husband does the computer and I do everything else.” Or: “We have a PC. My wife uses it to stay in touch with the grandchildren.”

In many partnerships it is clear that one partner is using the computer as the equivalent of a potting-shed, or bridge night, to get away from the other.

Internet use correlates strongly with income, and is lowest among the poorest sectors of society, although all local libraries offer free internet use. Many older potential users can't see the point. In an Age Concern survey, people who say they're “not interested” make up 44 per cent of those whom the Government describes as “digitally unengaged”, suggesting resistance to what's out there.

A further 20 per cent feel incompetent, and 25 per cent admit to fear. There are vague but rational fears about feeling a failure, suffering credit-card fraud or receiving spam, and fears of the cost of hardware. “I'm afraid I'll break the computer,” wailed a woman of fiftysomething whose husband had left her in a farmhouse in Italy to run a holiday business whose bookings are made by e-mail. Beyond fear, there is also resentment and anger, says Gill Adams, spokeswoman for Hairnet, the excruciatingly named organisation that offers older people IT training. “People say, ‘why do I have to do this?' They don't like feeling that the world has changed so much that the internet is communication.”

Another disincentive to use the internet must be the quality of those British online communities which consider themselves to be aimed at people over 50. Chatrooms and message boards can be a great resource for sharing experiences about everything from losing weight to coping with long-term illness, but the best are based on shared interest rather age range.

British websites such as the Baby Boomer Bistro — www.bbb.org.uk — which is operated by Age Concern, or I Don't Feel 50 at www.idf50.com, conceptualise their visitors as well into their second childhood. The least depressing in the UK is part of the Saga organisation at www.saga.co.uk, which has mastered the trick of treating its visitors like thinking beings.

Hairnet is building a nationwide team of 250 trainers who, for £20 an hour, will get an ageing newbie working on a computer. The trainers are mostly in their forties and fifties, and undertake not to gibber high-speed technobabble.

This year's Silver Surfers' Day on May 27 is being organised by Hairnet, which will announce its Silver Surfer of the Year Awards, and make computer training free for the day at venues in the UK, from local libraries, pubs, church halls and a GNER train.

It is also working with community groups, people in sheltered housing and care homes to set up Digital Unite Programmes to engage older people. “The programmes seduce even those people who might be wary of computers,” says Emma Solomon, its MD.

There is some evidence that once older computer users master the technology, they develop super powers, at least in the fields of sex and shopping.

The might of the grey pound is already in evidence with the over-55s spending more online than any other age group — an average of £527 per head in the UK last year, according to the retail analysts Verdict.

In the US, the pull of romance is stronger than ever for over-65s. More than a million senior Americans are looking for love and registration with internet dating agencies for silver surfers leapt 122 per cent last year. Now we know who buys all that cut-price Viagra online.