Apple will have to be quick to react to a software crack which makes it possible for unapproved software to be used on the new iPhone.
A teenager has moved away from normal hacker etiquette by making available an application that will enable users to download software onto iPhones even if it is not in the Apple App Store before Apple has a chance to create a fix.
He said he usually gives Apple a chance to work on the fix.
The jailbreaking tool has been made available to the public.
Hacker George Hotz said in his blog that he does not usually make these tools available to the public.
"Normally I don't make tools for the general public, and rather wait for the dev team to do it. But guys, what's up with waiting until 3.1? That isn't how the game is played. We release, Apple fixes, we find new holes. It isn't worth waiting because you might have the 'last' hole in the iPhone. What last hole this isn't golf. I'll find a new one next week."
In August 2007 Hotz demonstrated the first Hardware unlock of the iPhone using a technique that was developed by hackers. This allowed the iPhone to be used with any SIM card.
Apple is also working on a security patch for the iPhone to fix a vulnerability that could be exploited by cybercriminals.
The vulnerability in the way iPhones handle text messages was demonstrated by independent security adviser Charlie Miller at the SyScan security conference in Singapore. Miller demonstrated that he could use the vulnerability to temporarily disconnect an iPhone from the network, but did not give a detailed description of the attack method.
He has agreed with Apple to keep the details under wraps until the Black Hat security conference in Las Vegas on 25-30 July.