1. Download the Samsung Galaxy S Unlocker for Mac from this here:
http://www.multiupload.com/9NEBR6FAKD
2. Mount the DMG and drag the folder onto the hard drive. DO NOT DRAG THE ICON WITH THE LOCK (the app). Once the file is finished copying continue.
3. Open the application with the lock. It should open a terminal window. Let it run for a few seconds and then it should show a screen like this:
4. Write down your unlock code
For Windows UPDATED!!! With Un-Freeze Codes
Download and extract the attached Generate Unlock Windows.zip.
Run Generate_Code.bat
Look for the line Network Control Key:YourCode
Save the code
Step 2. – Enter the code
Power down your phone
Put in a SIM card from another carrier
Power up your phone
When it boots up it will ask for the unlock code that you found above
OR
NO SIM Method (Thanks RazvanG)
remove sim card
power on phone without sim
enter *7465625*638*# and relock the phone to another network other than the one u have u’r sim card (eg 22610)
power off phone
insert sim card back
power on and enter nck code extracted from .bak file
phone unlocked
Step 3. – Flash back (IF THE CODE DIDN’T WORK)
Flash back to an older firmware (I9000XXJF7 with 513.pit worked for me)
Now enter the unlock code you generated in Step 2.
Using the Market App
Search for Galaxy S Sim Unlocker in the market. (It is $10 and people say it works)
Originally Posted by RazvanG
HOW TO LOCK SAMSUNG GALAXY S – FOR WARRANTY PURPOSES ONLY (TESTED)
After you get the NCK code using the method above, enter: *7465625*638*#
There will be a pop-up box.
Complete the first field (MCC/MNC) with the network you want your phone locked to (eg. 226 10 where 226 = romania; 10 = orange etc.) and the second field (Control Key) with the NCK extracted from the .bak file.
Press OK and your phone should relock.
RazvanG
Guide in Spanish here
Guide in Italian here
Guide in Chinese here
LEGAL NOTES (because information should be free for all):
YOU MAY NOT, BY ANY MEANS, USE THIS SOLUTION/CODE OR PART OF IT FOR COMMERCIAL PURPOSES.
DO NOT USE THIS EXTRACTION METHOD COMMERCIALLY
PLEASE give credit (and donations if you can) to
For those of you that have donated THANKS! (You know who you are)
DaGentooBoyFor this AWESOME guide, the original mac and windows scripts, the no root cat nv_data method, the unfreeze code portion of the mac script, and a lot of troubleshooting 
(Paypal)
RazvanG for pointing galaxysguy in the right direction, finding the Freeze Code location in the .bak file, the code for re-locking the phone to any network, and the solution to unlock with only one sim card (Paypal)
rbnet.it and marcopon for the cool SGUX utility for windows to extract both the Unlock and Unfreeze codes (donate to marcopon and rbnet.it Here)
nbs11 for the new mac script that makes it REALLY easy (donate here)
Bowsa2511 for the command to extract the unlock code on a Mac (Paypal here)
rhcp0112345 for finding the file and giving me (and others) a place to start (Donate here)
galaxysguy for confirming that I was looking at the right code (Paypal here)
If you want me to extract the code for you just PM me with a link to your zipped bml3.bak or nv_data.bin file and I will send you back the code. If it works please feel free to donate via Paypal
