UK iPhone users have been warned that unlocking Apple's handset so it will work with other networks will prove a costly exercise.

Carolina Milanesi, a Gartner analyst who was at the UK iPhone launch in London yesterday, said she wondered if it matters much in the long run whether Apple stays a step ahead of hackers, as Jobs said it must do (see - Jobs: We will stop UK iPhone hacks).

"At the moment, as a consumer, you need to be very careful about unlocking the iPhone, and know how you want to use it," she said. "If you unlock it, you are not going to have a flat rate, and you will not have access to the 7,500 hotpots."

As reported yesterday, O2 will offer three flat-rate tariffs, ranging in price from £35 to £55 per month. Flat-rate plans are relatively rare in the UK, said Milanesi. "If you unlock and then use the internet and email, you may be surprised by your first bill," she added, referring to the pay-as-you-go data rates charged by most carriers in the country and elsewhere in Europe.

O2 has struck a deal with a Wi-Fi provider called The Cloud that will give iPhone users unlimited wireless access to some 7,500 hot spots in Great Britain and Northern Ireland.

"There's a difference here, too, compared to the United States," said Milanesi. Because Apple plans to release its iPod Touch, an iPod-cum-internet device, in the UK by the end of the month, consumers will have a choice between that and the iPhone when the latter launches five weeks later.

"Now with the Touch, you have an alternative," she said. People who might have been drawn to the iPhone for its music capabilities, interface and/or its web browsing features - and might have used an unlocking hack so they could avoid paying a penalty when they ditched their current carrier - could instead opt for the iPod Touch.

Jonny Evans and Karen Haslam of MacWorld UK contributed to this story.

See also:

How to unlock an Apple iPhone for free

O2's UK iPhone sacrifices revealed

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Apple iPhone: the definitive review

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