Almost as soon as Apple released iOS 5.1, hackers figured out how to jailbreak it… on some devices. Jailbreaking allows you to access hidden files and settings and install apps that aren’t available from the iTunes App Store.
Right now you can’t jailbreak iOS 5.1 on a device with an Apple A5 processor and if you do have a supported device, you can only perform a tethered jailbreak, which means you’ll need to connect your device to a computer any time you reboot it.
If those limitations don’t bother you, head on over to the iPhone Dev Team blog to find the download links for redsn0w 0.9.10b6 for Mac or Windows. Connect your iPhone, iPod touch, or iPad running iOS 5.1 to your computer with a USB cable, fire up the app, hit the Jailbreak button, and follow the on-screen directions.
Right now there’s no way to jailbreak the iPhone 4S, the iPad 2, or the new 3rd generation iPad. That’s because the first two have the Apple A5 processor while the latter has the new A5x processor. The exploit redsn0w uses to jailbreak iOS 5.1 right now doesn’t support those chips.
But if you really need a reliable jailbreak and don’t desperately need a new camera icon on your home screen, the ability to delete photos from Photo Stream, or Japanese support for Siri, there aren’t a lot of reasons to update to iOS 5.1 in the first place. It really doesn’t offer many features that you can’t get from iOS 5.0.1.