If you got yourself a Samsung Galaxy S 4G, you no doubt are loving the 4G speeds. But what if you’re curious on what the other networks are like with that Galaxy S of yours?
After you give yourself root access to your device, you’ll also need to grab a hex editor to be able to get your device operating on another network. The file that contains the code is called “bml3.bak”. Once you have that file, you’ll need to do a hex search for an 8 digit code, which is the Network unlock Control key. Once that’s changed, you’re laughing.
For details and full instructions, hit this thread. Also, hack cautiously.