How to use an iPhone 5 abroad?

I have an iPhone 5 that I purchased and have been using in the US I will be traveling to South Korea this year for an extended period of time and I was wondering if there was a good way of using that iPhone over there without unlocking it or anything like that. An ideal way for me, personally, would be to just simply purchase a plan over there and place the SIM card into the iPhone. Since it's not that easy, I was wondering what my alternatives would be.

Get it unlocked

  • Will i still be charged if i use my iphone abroad only on Wi-Fi? I'm going to thailand. I don't want to pay for data charges abroad. My iphone is on contract with o2. If i turn off my mobile data and 3g. And will only use Wi-Fi when i can connect to free Wi-Fi over there, will i be charge?
  • What to turn off on your iPhone when going abroad? I'm going away today and i need to to know what to turn off so I'm not going to charged AT ALL. Every last bit please! And also if i connect to a free Wi-Fi abroad will it charge me? And what does it mean by in notifications where it says sort apps "manually" or "by time"?
  • Tmobile Iphone 5 use abroad? I recently bought an Iphone 5 through Tmobile. I have unlimited data, text and calls. I will be traveling to Mexico in two weeks and want to use my phone for texts or to check emails (no calls) will I be charged for using my phone eventhough I have unlimited data and texts.
  • Is it possible to use a CDMA 1429 iPhone 5 abroad? Is it possible to use a CDMA 1429 iPhone 5 abroad using a GSM sim? Of course I'll have it unlocked from Sprint first. I'm just wondering if it's ever possible.