It's official, BlackSn0w is out and available for download. BlackSn0w is not a standalone app. BlackSn0w is part of Blackra1n RC3.
People who accidentally locked their iPhone on baseband 05.11.07 will now be able to unlock their iPhone using BlackSn0w.
This step by step guide and tutorial will show you how to unlock your iPhone OS 3.1.2 baseband 05.11.07 with BlackSn0w.
If you just want to jailbreak your iPhone and are not interested in unlocking, refer to my BlackRa1n RC3 tutorial.
This BlackSn0w iPhone unlock tutorial will work on both Mac and PC.
In this tutorial, I will assume that your iPhone is currently not jailbroken or unlocked.