A hacker has created a website that will jailbreak iPods, iPads and iPhones running almost any version of iOS, freeing the devices from software restrictions placed on them by Apple.

Users who want to access unauthorized apps or use their phones in multiple countries, for example, can surf to http://jailbreakme.com/ to hack their devices.
The hack comes about a week after the Library of Congress, which operates the Copyright Office, decided that jailbreaking is not illegal. Apple discourages jailbreaking, claiming it represents a threat to the security and stability of its devices.
Jailbreaking will void the warranty on a device, Apple says. However, the action is easy to undo by resetting a device to factory settings (and will be undone by downloading any new version of Apple’s mobile operating system, iOS).
“JailbreakMe” quickly jumped into the trending topics on Twitter after the announcement on tech news site Redmond Pie. This is possibly the first browser-based jailbreak. In the past, users would jailbreak their phones by downloading an app onto their computers and connecting to the device they wanted to jailbreak.
The jailbreak is credited to hacker comex and the website is credited to westbaer and chpwn. Hacker Clayton Braasch posted an FAQ here. An alternative link to the jailbreak is available at http://jailbreakme.modmyi.com/.
Users who downloaded the jailbreak are reporting that the jailbreak works on any device and software combination except an iPad running 3.2.1 (and possibly devices running the unreleased iOS 4.0.2). The jailbreak works by navigating to the site in Apple’s default browser Safari and “sliding to jailbreak.” The process can take as little as a minute to download, declare that it’s added itself to the home screen, and tell you to “Have fun!”
Jailbreaking lets users download unapproved software such as the MyWi app, which turns your iPhone or iPad into a wireless hotspot, and WinterBoard, which allows users to customize the way backgrounds and icons appear. It can also allow users to hide native apps that Apple doesn’t let you remove, such as Safari.
Jailbreaking also makes it possible to unlock the iPhone in order to use it with a carrier other than AT&T.
UPDATE: Some users are reporting that this jailbreak interferes with Facetime and Multimedia Messaging on the iPhone 4.