Unlocking Iphone 4S - consequences?

I want to by the 4S or the 5 (if I see a good deal) but I'll order it from abroad because its cheaper. The thing is some are locked to foreign companies such as O2, Vodaphone, etc. If I take my Iphone to someone to make this limitation disappear how will it affect the devise? Will I be able to access Itunes, download new apps, updates, etc?

Unlocking just means letting it be able to use any carrier, it won't affect your apps in any way.

  • Unlocking sim for iPhone 3gs? Ok, so I've been having a lot of trouble with trying to unlock my iPhone. I jail-broke my phone a month ago and I have cydia and all that stuff, and I don't think that's what you use to unlock the simcard. Maybe it has something to do with the firmware? It's 05.16.05. If I have to update the firmware, or download something on my phone please tell me. I just want to use the phone.
  • Unlocking iphone from rogers? How do i unlock a phone from rogers? My cousin gave me his old iphone 3g but its still locked. I want to use it for koodo, so i bought a new SIM card today, thinking that i could unlock it myself, but it seems really difficult, i don't want to buy software to do it. Do i have to jailbreak it to unlock it? And how do i unlock it easily?
  • Unlocking Iphone 4s outside USA? One of my uncles bought me an i phone 4s from USA. But it's a locked version so I can't use it here in Sri Lanka. Can I know is there any way of unlocking the Iphone safely? And what happens to the contract with at&at if I unlock it here? Do we have to pay anything to at&at or something? I can't buy an unlocked Iphone because it's too expensive for me.
  • Unlocking iphone 4S effects for other gsm providers outside US Brought a iphone 4S in US as i'm shifting to another country permanently i want to get my phone unlocked to all gsm connections outside US I will not install 3rd party apps just want to use an another gsm that's all. My question is what are the disadvantages of unlocking an iphone? I'm afraid my battery drains very fast and the os will be unstable is that so?