By sheer serendipity, some nerds over xda-devs managed to locate the unlock codes for Samsung Galaxy S and its variants including Captivate (AT&T) and Vibrant (T-Mobile). Surprisingly, unlock code for the said handsets are stored in a .BAK file on the internal SD card instead of keeping it in a secure remote server.
Once unlocked, you can easily run a T-Mobile Vibrant on AT&T’s 3G network and an AT&T Captivate on T-Mobile’s network, though the Captivate reportedly only connected via EDGE. Don’t you worry! The process will not void your warranty as it does not require you to root your android phone. The handset can be re-locked easily, in case if you have to return a handset for warranty claims.
How to Carrier unlock Samsung Galaxy S, Captivate and Vibrant
Switch between carriers of your choice is simple. Just mount your Samsung android phone via USB, copy the file onto your desktop, and run a script to extract the unlock code. Darn simple! Isn’t? If you are not geeky enough, you may download the Galaxy S SIM Unlocker from the Android market to extract the code automatically, but you need to shell out $10 for the goodness.
Guys over Engadget has used the method devised by xda-devs to carrier unlock Samsung Captivate and Vibrant successfully. If you too are annoyed with slow AT&T network and want to switch carrier (T-Mobile), then follow full step by step instructions to SIM unlock the Samsung Galaxy beast.
Via – Engadget