Armed with a soldering iron and a large supply of energy drinks, a teenager has developed a way to make the iPhone, arguably the gadget of the year, available to a much wider audience.
George Hotz of New Jersey spent his last summer before college figuring out how to "unlock" the iPhone, freeing it from being restricted to a single carrier, AT&T Inc.
The procedure, which the 17-year-old posted on his blog on Thursday, raises the possibility of a small industry springing up to buy iPhones, unlocking them and then selling them to people who do not want AT&T service or cannot get it, particularly overseas.
The phone, which combines an innovative touch-screen interface with the media-playing abilities of the iPod, is currently sold only in the US
An AP reporter was able to verify that an iPhone Hotz brought to the AP's headquarters on Friday was unlocked. Hotz placed the reporter's T-Mobile SIM card, a small chip that identifies a phone to the network, in the iPhone. It then connected to T-Mobile's network and placed calls using the reporter's account.
T-Mobile is the only major US carrier apart from AT&T that is compatible with the iPhone's cellular technology, but smaller carriers also use the technology, known as GSM. In Europe and Asia, GSM is the dominant network technology.
The hack is complicated and requires skill with both soldering and software, and missteps may result in the iPhone becoming useless, so few people will be able to follow the instructions.
"But that's the simplest I could make them," Hotz said. The next step, he said, would be for someone to develop a way to unlock the phone using only software.
AT&T spokesman Mark Siegel and Apple spokeswoman Jennifer Bowcock said their companies had no comment. Hotz said the companies had not been in touch with him.
Apple shares rose US$4.23, or 3.2 percent, to close at US$135.30 on Friday. AT&T shares gained US$0.26, or 0.7 percent, to close at US$40.36.
The iPhone has already been made to work on overseas networks using another method, which involves copying information from the SIM chip.
The SIM-chip method does not involve any soldering, but does require special equipment, and it does not unlock the phone -- each new SIM chip has to be reprogrammed for use on a particular iPhone.
Both hacks leave intact the iPhone's many functions, including a built-in camera and the ability to access Wi-Fi networks. The only thing that will not work is the "visual voicemail" feature, which lists voice messages as if they were incoming e-mail.
Since the details of both hacks have been made public, Apple may be able to modify the iPhone production line to make new phones invulnerable.
Analysts said it is unlikely Apple would overhaul the iPhone's wiring to thwart the new hack because the difficulty of the procedure is likely to keep it confined to hardcore hobbyists.
"I'm having a hard time figuring out where the real pain is going to come from in this," said David Chamberlain, principal analyst with market researcher In-Stat who follows mobile devices and services. "Just selling the piece of hardware, they've made a nice profit off that."
Apple has said it plans to introduce the phone in Europe this year, but it has not set a date or identified carriers.
There is apparently no US law against unlocking cell phones. Last year, the Library of Congress specifically excluded cellphone unlocking from coverage under the Digital Millennium Copyright Act. Among other things, the law has been used to prosecute people who modify game consoles to play a wider variety of games.