The U.S. Amazon already has the unlocked GSM Samsung Galaxy S III up for pre-order. For folks that want the freedom to take the phone to any GSM network, that freedom will set you back a penny or two. The phone is selling for a bone-crunching $864.49. If you have deep pockets or simply the justifiable need to have this unlocked and off-contract version of Samsung's latest flagship, then hit up the Amazon source link below.
Thanks for the tip, RobKort!