Hackers striving to 'unlock' Apple's iPhone so that it will work with any SIM card inside it said today they were within hours of reaching their goal.

Since Friday evening, a community of hackers around the world have been exchanging details about the iPhone's system in an attempt to understand how to 'activate' the device with any SIM card - including a European - rather than those of AT&T, the exclusive carrier of the phone.

A successful hack would mean that the iPhones that have now gone on sale eBay for as much as $1,000 could be made to work in Europe, even though the device is not due out here until the end of the year, experts said.

By this afternoon, a post on one of the main forums in which would-be Apple hackers are congregating purporting to reveal details of the software on which the iPhone runs had been read more than 61,000 times.

"We know how unlocking of the phone occurs with a reasonable degree of confidence - we cannot yet trigger this unlocking or verify whether we are right but speaking for myself, i'm pretty sure I know how to do it " a post by 'gj' on iPhone Dev Wiki, read.

An update yesterday evening said: "I think by tomorrow night we'll have an activation crack."

Pictures posted on another site, www.howardforums.com, gave advice of how to remove the phone's existing SIM card: "Insert the end of a small paper clip into the hole on the SIM tray. Press firmly and push it straight in until the tray pops out," the instruction read.

A European-based group of hackers was asking colleagues to contribute towards the $500 cost of the iPhone so that a model could be shipped from the US and taken apart for analysis.

The iPhone, which went on sale in the US on Friday, was today selling on eBay for anywhere between $499, the retail price, and $1000, making the prospect of a successful hack tempting for Apple fans in Europe, who will not see the device in stores until the end of the year.

Apple maintains that the phone is securely locked to the AT&T network, but most mobile phone handsets have in the past been able to be unlocked, usually for a fee of between £5-10.

A blog called unlockuriphone.com was offering to unlock iPhones for "a small fee" as soon as it had cracked the code, asking owners to send details of their phone's International Mobile Equipment Identity (IMEI) - the number which identifies each handset individually - in order that it could be untethered from AT&T.

"With a release as high profile as the iPhone, there's enormous kudos for the successful hacker, not to mention a potential income astream in handing over the code," Paul Vlissidis, technical director with NCC, a security firm, said.

"There's no reason why, once hacked, the phone won't work in Europe - it's a bit like Region Zero DVDs. Every phone is made to work with every SIM; it's just a matter of cracking the network lock that the manufacturer and the operator have agreed upon."

Sam & Max on Tour, a contributor on the forum Hackint0sh who promised to make the 'hack' public once it was successful, said: "We are not into making money with our stuff, we do it with fun and not for profit."

Asked whether what he was doing was illegal, he said: "No, we don't live within the US, there are a lot free countries that allow you to break or modify stuff on your own."

Not every forecast for a successful hack of the iPhone was so upbeat, however. A post on Mac Rumors, another forum for Apple users, said: "All current claims to people owning an unlocked iPhone are false. To this date no one I am aware of has successfully unlocked an iPhone."

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