Pro: Rebellion Against 'The Man'
Apple argues that by keeping firm control over the hardware that runs its software, it's able to maintain quality and a consistent experience. But with all the App Store rejections, limitations on software developers, and usage restrictions (MMS is here finally, but where is tethering?), some people feel constrained by what the iPhone can't do. Apple has been very clear that it isn't happy with iPhone hacking, so if you're the kind of person who likes to rush out of the electronics store without letting the security guard check your receipt, you may find a rebellious thrill in jailbreaking.
Pro: Third-Party Apps Galore
Cydia and its newer, lighter competitor Icy are the unofficial app stores available only to jailbreakers. In these stores, you'll find hundreds of terrific apps that have been rejected from the App Store for providing features that Apple would rather you not have. Examples? Cycorder is a camera app that enables video-recording on pre-3GS iPhones; PDANet allows tethering of your 3G connection to your laptop; and GVMobile is an app for the Google Voice service. Plus, you can still get free and paid apps from the official App Store, so jailbreakers get the best of both worlds.
Pro: Total UI Customization
The iPhone's user interface is excellent, but there is just something cool in giving your phone a Snow Leopard facelift. Or making your home screen look like a vending machine. Jailbreaking lets you do that, and much more. With the Winterboard app, you can install any of the vast number of skins available. Jailbreaking also lets you install systemwide add-ons such as SBSettings, which enables quick access to your system settings from within any app. You can even add a fifth icon to the dock at the bottom of all iPhone screens or change system sounds (like adding some new text message tones to the scant built-in set of six). The list goes on and on.
Next page: The Cons