The Dev Team has released UltraSnow, the software unlock for iPhone OS 3.0 that replaces yellowsn0w. Yellowsn0w is the originary sn0w that started the pwnage-oriented joke of color-coded territorial piss marking. Cute, and funny, but rather confusing at times since each snow color release actually accomplished different things. (See key terms here.)
This release completes the hat trick of releases over the past week that update the jailbreak tools for OS 3.0. First, Pwnage tool was released for Mac OS X, then RedSn0w was released as a cross-platform successor to QuickPwn, and now UltraSnow makes carrier unlocking possible on OS 3.0.
The Dev Team is owed great gratitude by all the jailbreakers out there for their quality work. So thanks! Although days behind their own announced release ETAs, the cycle is now complete. Watching the tens of thousands of comments on the Dev Team blog, it became abundantly clear that people were waiting for each release with a lot of impatience and frustration, many having upgraded to OS 3 before a jailbreak was available, or while needing the carrier unlock to use their phones, despite warnings to wait. It also became clear that many people never understood the distinction between jailbreaking and unlocking.
UltraSn0w is available via Cydia after adding repo666.ultrasn0w.com to your sources.