Once the 3g iphone is unlockable will it work on other carriers like Sprint? I guess I am not familiar with cellular/3g technology. Is there a standard SIM card like the current iphone uses? (i would guess so, just not sure). Does that also mean the japanese softbank service uses a SIM and that once the 3g iphone is unlockable it will work around the world just like the current iphone works for tmobile?