These are instructions on how to jailbreak and unlock your iPhone 3G and 3GS using BlackRa1n and BlackSn0w for Mac.

These instructions will work with the latest 3.1.2 firmware, the 05.11.07 baseband, and iPhones which require hactivation.

For those with a new iPhone 3GS (updated Bootrom), BlackRa1n only supports a tethered jailbreak. This means that once jailbroken you should not let your battery die. If it does die you will need to reconnect it to the computer and use BlackRa1n to boot it.

Before continuing make sure you are on the 05.11.07 baseband by following this tutorial. If you are not please update your firmware to 3.1.2 using iTunes before continuing.

You can find the Windows version of this tutorial here. Ok lets begin…

Step One
Open your web browser of choice and navigate to http://www.blackra1n.com. Click the Apple logo at the bottom of the screen.

Step Two
When prompted save the download to your desktop

Step Three
Then double click the downloaded blackra1n zip file to extract the application, then double click the application icon to launch the program

Step Four
Make sure your iPhone or iPod is connected to the computer then click the large make it ra1n button

Step Five
You iPhone will now be placed in recovery mode.

You will see a picture of GeoHot that replaces the regular recovery mode screen on your device.

blackra1n will run and then your device will reboot.

A popup message will appear informing you that BlackRa1n is free software and if you appreciate it you can donate to GeoHot at geohot@gmail.com.

Step Six
Once your device reboots it will be jailbroken and you will notice a blackra1n icon on the Springboard. Make sure you have an internet connection and press to launch the application.

Choose the installer application of your choice then press to select sn0w if you would like to unlock your device. Press the Install button at the top right of the screen to begin.

BlackRa1n will begin to download and install the packages you selected.

If you chose to unlock device using blacksn0w you will be presented with a Post Install log for sn0w. CommCenter will be restarted and there is no need to reboot. If your carrier doesn’t support 3G then disable it. Press the Close button to continue.

Step Seven
Once complete BlackRa1n will respring your iPhone and you will find the installer package of your choice on the Springboard.

Step Eight
Once you have confirmed your installer package is working correctly you may use the Uninstall blackra1n button inside the BlackRa1n app to remove it from your springboard.

thank http://www.iclarified.com/

Geohot has announced that an unlock dubbed BlackSn0w for the iPhone 05.11.07 baseband is coming soon.

This means that all iPhones will be unlockable; including those that have accidentally or intentionally upgraded to the latest firmware.

hello there, this is geohot
this is the most complicated injection i have ever done, and it uses a public command
… prepare for blacksn0w, although i gotta still figure out this zamboni

We will of course keep you up to date with further developments but things certainly look promising. Keep up the good work Geohot!