A hole in the iPhone's software allows any user to bypass the security code on the gadget allowing unauthorised use of the holy handset.
Orginally exposed by a bloke on MacRumours' forum who had apparently been fiddling about with his jailbroken phone, the simple hack has been shown to work on any iPhone jailbroken or not.
So if you have your iPhone handy try this:
Lock it with your usual security code, then tap the screen on the 'make an emergency call' button. Enter ### and "call" then immediately hit 'lock'. You should then have access to a number of the phone's features, including the call history address book and the photo app. There may be more.
Here's a Vimeo video of the hack posted by a user in Brazil.