Its been discovered that Samsung have kindly installed a file on their Galaxy S and the US versions, the AT&T Captivate and T-Mobile Vibrant smartphones, with the codes necessary to unlock the devices very easily.
The tricky part is actually accessing the file that contains the codes. But the nice team over at xda-developers have created a tool to help you out. It simple takes a locked Galaxy S family smart phone and converts the device into a nice unlocked version for you.
All this can achieved without even having to root your device before hand. But please remember there are always risks involved with unlocking your phones that could result in bricking the devices completely.
You can follow the instructions here: xda-developers
Via Slash Gear