I am planning to be out-of-country (I am in Canada) for a month or so, and there is no way I am going to use my canadian wireless carrier roaming. I am going to use local SIM cards in the country where I go. I understand that iPhone is locked. Can I temporarily jailbreak it to unlock and use other carrier's SIM card? And then when I come back I would like to restore it back, because I don't really want to have it jailbroken forever. I need it only for traveling. The alternative is just to buy a cheap handset in the other country and use it instead of iPhone. But I would prefer to use iPhone, I am so used to it. I am just wondering, how easy it is to restore it after it has been jailbroken? Is this a right way to unlock iPhone - to jailbreak it? How safe is it for iPhone? I have iPhone 3G OS 3.0. Thanks!