Well, it seems as if the jailbreaking community has certainly been busy these past few days, first with the Safari-based jailbreak, then the release of FaceTime over 3G, and now the first iPhone 4 carrier unlock. Ultrasn0w version 1.0-1 provides iPhone 4, 3G and 3GS owners the ability to carrier unlock their iPhone to work across multiple providers.

A carrier unlock on the iPhone allows the device to use carriers different from the one set by Apple (AT&T). This is very useful if you do not have AT&T coverage in your location or if you used a different carrier before switching to the iPhone. Ultrasn0w is downloaded via Cydia, and therefore you must have your iPhone 4 jailbroken before a carrier unlock can be done. Please proceed at your own risk.