Hey all, I'm going to hong kong on Thursday and in preparation I have had my phone unlocked by my carrier so I can use a cheap sim card there. I have two questions... Because I am leaving on Thursday, I am going to put my original sim card back into my iPhone and change it on Thursday. Will the iPhone remain unlocked when I do this, or because I put the original sim back in willit relock to that carrier? My second question is will a hong kong sim card work for my Australian iPhone? Thanks!