In a recent poll by GQ magazine the chief executive of Tesco, Sir Terry Leahy, was voted as the most powerful man in Britain outside the Government, second only to Prime Minister and Chancellor.

The 49-year-old retail supremo has helped to make Tesco Britain's fastest growing clothing retailer as well as the nation's favourite supermarket - £1 of every £8 spent on the high street goes to his stores.

The tag line Tesco uses on its adverts, "Every little helps", was brought home to me on a recent trip to the supersize Tesco in Gilesgate, Durham, with the discovery of that unfortunate development in retail technology: the self-service, self-scan checkout. I hadn't thought "every little helps" translated as "that includes you doing your own scanning and packing".

As a man I obviously like to think of myself as technologically gifted. When I buy the latest electrical gizmo my testosterone urges me to discard such pitiful manuals as operating instructions in the dustbin as I get to grips with modern technology. However, the self-scan checkout proved a technological advance too far.

When I've been shopping before at this store late at night, there have been about half a dozen people working on the tills. But with the introduction of the new technology, the number of real people on offer had been cut down to two and consequently the queues were much longer.

The self-checkout queue, however, was empty. Theoretically, this meant that it would be quicker if I went to the self-checkout till. Experience disproved that particular theory.

As I attempted to scan the contents of my trolley, a disembodied female voice would tell me that the product I had just placed on the conveyor belt was not on the belt, or that the weight of the item I'd placed on the belt didn't measure up against what the computer thought it should be. I lost count of the number of times Sharon, the late night supervisor, had to come over and reset the system with her special code to enable me to continue the torture.

Of course, there is research to back up the proposal that people now want to check out and scan items for themselves. My experience places me firmly outside this finding. Not only is there the dubious pleasure of publicly humiliating myself by not being able to operate machinery designed to be wholly idiot-proof, there is the added worry that I'm playing into the hands of this corporate giant.

Self-service checkouts mean fewer jobs; fewer employees in order to make more profits.

Tesco has taught me that advances in technology aren't always good. Self-service checkouts mean less human contact and increased frustration. They don't help a lot and they certainly don't help a little.