Apple is the exclusive gatekeeper to its iPhone App Store, able to reject apps at will - as it did July 28 with Google Voice. But some developers aren't taking the rejection lying down: They're turning instead to an unauthorized app store called Cydia, where forbidden wares continue to exist - and even earn developers some money.
That store is operated by Jay Freeman, more fondly known in the iPhone "Jailbreak" community as Saurik. Only five months old, his app store Cydia specializes in selling apps that Apple would reject or ban (or already has). To use Cydia or the apps available through it, customers need to jailbreak their phones - hack them to work around Apple-imposed restrictions - a process that Apple claims is illegal.
Indeed, you can even get a Google Voice app, GV Mobile, through Cydia. After Apple pulled the app from its App Store, developer Sean Kovacs (who is not affiliated with Google) made it available for free through Cydia.