It looks like we're about to see a jailbreak for iDevices: good news for users who want non-AppStore apps. It's even working for the new iOS 4.02 and 4.1. Listen up, if you want the latest operating system, or you've accidentally upgraded to it (specifically, if you own an iPhone 4, iPhone 3GS, iPad, or iPod Touch 4G). It's a bootROM exploit, which appears tricky for Apple to fix (oh boo-hoo, how terribly tragic).
Hackers almost immediately try to jailbreak any new release from Apple with the intention of running unauthorized software. He adds that over a million owners having already jailbroken their devices in order to get apps from other sources rather than paying for them through Apple’s iTunes Store.
Users may want to think twice. ... In February, Apple filed for a patent that covers the ability to spot and disable various unauthorized uses ... jailbreaking included.
By jailbreaking the device, you may not only be voiding the warranty – but you may one day end up with a bricked phone or MP3 player..