Most times, the slightly-embarrassed Mr Smith will hand over his details without questioning, as the call will indeed appear to come from reception. Armed with this information you can now call the credit card company and order your own card at Mr Smith's expense by changing the address of the account to one of your choosing. Ideally, the company will be one of those that allows you to order cards for friends and relations on the same account, so you can even get your own name on the card and not risk using one with a name that doesn't correspond with your passport. Easy, eh?

It's one of the many simple but ingenious methods used by Elliot Castro, the fraudster that became the bane of international credit card companies before he was finally apprehended in 2005. The most astonishing aspect of Castro's career as a criminal though isn't that his spending spree ran well beyond seven figures, or that no one had stolen so much for so long from the credit card system, but that when he was finally caught after evading justice for over five years, he was still only 22 years of age.

Journalist Neil Forsyth first encountered Castro in The Scotsman newspaper. The article told how a young conman had tricked his way around the world and into affluent society by taking on various guises and compared him to the Leonardo DiCaprio character from Steven Spielberg's Catch Me If You Can. Forsyth went to meet Castro for a magazine article, and found himself fascinated with this young kid who was basically an old-fashioned confidence trickster with a working knowledge of new technology thrown in.

Frustrated at being only able to scratch the surface of a deeply complex character and a fascinating story, he persuaded Castro to work with him on a book of his extraordinary tale.

Castro was born in Aberdeen in 1982 to a Scottish mother and an Italian/Chilean father, but despite being precociously intelligent with a photographic memory he found himself bounced around through various schools because of his disruptive influence, never settling into or enjoying education. He developed a fascination with travelling and the moneyed lifestyle of the wealthy, a world that the teenager was to successfully infiltrate to the degree that he was hanging out with Bono in the Clarence and staying in the world's only seven-star hotel, the Burj alArab in Dubai. Unsurprisingly the film rights have been sold.

But none of the money stolen was to pay for an addiction; rather the stealing was an addiction in itself. "There was a frantic nature to what he did, " agrees Forsyth, "So there was always likely to be an escalation. You're not going to get the same buzz off stealing �1,000 the second time you do it and certainly not the tenth. I have lots of the receipts and records from the court case and it's amazing to see him move gradually from �10.53 in a WH Smith to the point where he's buying �12,000 Rolexes."

Castro comes across as being an odd combination of very mature and smart on the one hand, and occasionally very childish on the other, although perhaps this is unsurprising for someone who led a life that was utterly detached from reality from the tender age of 16. He never paid a bill or filled out a CV in his life, moving straight from normal childhood practices like skipping stones across the river, to flying around the world and spending vast amounts of money that very few people would earn over the course of their lives.

Throughout all this time and with numerous close shaves, Castro constantly managed to stay one step ahead of the police, and while there were brief, and horrific, stays in prison, he always managed to disappear again before the police forces in various countries could work together to close the net on him. He even occasionally took to calling the people that were chasing him and taunting them, including the Irish police. Aside from his stays in The Clarence Hotel (and a brief stop-off in Cloverhill Prison) there were also numerous shopping sprees on Grafton Street that were funded by unknowing others, and tasked with doing most of the chasing for Castro's offences in Ireland was a man called Declan Farrell.

As Forsyth explains, "A lot of the stuff Elliot did was just rubbish, which I think makes the story a lot funnier and a lot more human, that he wasn't just some robotic figure. He was trying things out all the time and occasionally would cock things up spectacularly. So at one point Elliot decided to call Farrell and, despite being in Ireland at the time, he had this great plan to convince Farrell he was actually in France. But Elliot could only remember one phrase in French which was, 'Can I have a baguette?' So he kept turning around during his conversation with Farrell and shouting this phrase and through all this Farrell is laughing at him, saying, 'Put the Frenchman on Elliot.'

"But every policeman I spoke to about Elliot enjoyed talking about the case cause I think for them it was something different, definitely a different type of crime and certainly a different kind of criminal."

His life on the run eventually became untenable after he chose Belfast as a base for his worldwide excursions. Having elements of a normal life, including an apartment and, for the first time, friends, meant that things started to get complicated as he could never tell any of the people around him how he maintained his extravagant lifestyle. Eventually, capture by the authorities was the only way out of the cycle he had created for himself.

When the long arm of the law eventually grasped Castro, the man who had managed to pull all the disparate strings of his many offences together was Ralph Eastgate, a policeman nearing retirement and working out of an office in Heathrow Airport with an almost geeky interest in fraud. "Eastgate told me the biggest challenge he had in putting the whole case together was persuading the banks and credit card companies to give him the information, " says Forsyth. "They're so secretive and edgy about putting information out into the public domain that could possibly be used against them by competitors, or that would maybe knock consumer confidence that he really had to battle to get the information he did, and even at that he only got a proportion of it.

"I'd very firmly believe after writing the book that credit card companies would prefer, in cases like Elliot's, to pay people off rather than go to the police. And there is a lot of stuff that Elliot did that the companies were aware of that never reached the police because it's in their interest to keep publicised levels of fraud artificially low, because otherwise it becomes too big a story and it knocks credit card holder confidence. If people thought they were in danger of getting ripped off by an 18-year-old kid they're going to be a little less enthused about the service."

Oh, and if you're planning to launch a career as an international fraudster, best to ignore the opening paragraph of this article.

"We've disguised most of the methodology to an extent, " explains Forsyth, "as the publisher felt under pressure from a legal viewpoint that the book could be used as a manual on how to steal." Damn.

'Other People's Money: The Rise and Fall of Britain's Most Audacious Credit Card Fraudster', by Neil Forsyth with Elliot Castro, is published by Sidgwick and Jackson, /18.99