thought I should share it. I have just been into the local Telstra office where I purchased my iPhone 4, I asked them how much it was to have my phone unlocked and they told me that if your phone is upgraded to ios7 that it is already unlocked and you can use any sim in the whole world as long as it is the right size. BONUS! Means there is no need to buy a Bali phone, just the sim and then I just pop my Telstra one back in when I get home. Too easy :)