The jailbreaking community was caught off guard yesterday when hacker group evad3rs released an untethered jailbreak for iOS 7 devices, about 3 months after the revamped OS made its debut. Dubbed evasi0n7, the exploit allows you to gain what would be the analog of administrator privileges over your iPhone, iPad or iPod device. But we're not going to go through what jailbreaking is, and we'll just assume you know why it is you want to jailbreak your device.
Anyway, onto the procedure itself. It's actually exceedingly simple, and it's suitable for even the average iOS user, though we should warn you that any meddling with your device can have potentially unpleasant consequences. Therefore:
We absolutely recommend you backup your device with iTunes/iCloud before you give this a go. This way, if something goes wrong, or you wish to remove the exploit, you can do so easily and without any loss-of-data hassles.
All backed up? Good! Now ensure that your iOS version is actually crackable by going to Settings > General > About > Version. The current exploit only works for iPhone, iPad and iPod devices running iOS 7.0 through 7.0.4.
If you have used an OTA (Over The Air) update in the past, the developer team recommends you use iTunes to revert back to iOS 7.0.4 to avoid complications. Save yourself the a potential headache and do it.
Disable your passcode if you have one in place, as this is known to cause issues. Go to Settings > General > Touch ID & Passcode > Turn Passcode Off.
Download evasi0n 7 for Mac (10.6 minimum!) or Windows (XP minimum!). Once installed, just extract the executable file from the archive and power it on. We assume that your device is already plugged to the computer, as you didn't forget to back it up via iTunes. If so, the small program will detect your device and list it as supported. Click the 'Jailbreak' button and do not interact with your device or iTunes in any way until prompted (at about 60% of the progress bar). You'll be then asked to unlock your iOS 7 device and tap the 'evasi0n 7' icon. Go ahead and do as instructed. The process will then continue, and you'll be asked once again to unlock your device.
Once the process is done, navigate to the second homescreen and launch the 'Cydia' app. Don't touch your device while it prepares your file system. It'll take a short while, and your device will then restart. Voila! You're now officially jailbroken.
The Cydia store will ask you for an upgrade, go ahead and opt for the complete update. Do keep in mind that the alternative store is still stuck in the iOS 6 era, so it'll clash with your UI visually. Updates to Cydia, along with a bunch of other jailbreaking essentials are expected to come soon, though there's obviously no specific date.
That's it, folks, enjoy your freshly jailbroken iOS 7 device. If your device becomes unresponsive during the process itself, you can just put your device in 'DFU' mode (Device Firmware Upgrade) and restore it. For more specific issues, you can likely get help from evad3rs' support page, found here.