AFAIK (and some google searching seems to confirm) the Galaxy SII does not have a locked bootloader. I believe that the original Galaxy S was also unlocked. So

AFAIK (and some google searching seems to confirm) the Galaxy SII does not have a locked bootloader. I believe that the original Galaxy S was also unlocked. So which Samsung Android devices have locked bootloaders? Motorola and HTC tend to lock their bootloaders more often (though this situation is improving).