Doesn't Apple make a CDMA phone for Korea?
My understanding is that Korea is NOT on the GSM standard.
Your friend should contact Apple in Korea and a Korean network provider for IPhone to be sure this will work.
It may be that the european iPhone could roam in Korea (with huge costs).
If no providers in Korea can offer a SIM then your friend would be out of luck.
Apple is making a CDMA phone which has been traced to an Asian factory.
Yes Malcolm, the iPhones in Czech are unlocked (that's great:)). My friend is Korean so she should be able to get the korean SIM card easily.
I've just found one information, that all Korean cell phones has registered IMEI number so that cell phones from foreign country with Korean SIM card may not be working. Do you know something about that?