I have just inherited a Galaxy S Captivate (ex US At&T model of Galaxy S) and it is currently "unlocked" and so will work with any NZ carrier. I don't really understand what this unlocking business means and want to know: If I install the latest iteration of Android on this phone (which a google search revealed can be easily done via a PC by downloading Kies Mini), will I "re-lock" this phone rendering it unable to connect to NZ networks?
It is currently running 2.2 Froyo and would like to upgrade to 2.3 Gingerbread.
So I went ahead and did this, and it turned out not to be as simple as I had hoped. The official Samsung Kies software did not like my phone for some unknown reason so I had to use an unofficial firmware. I now have 2.3.5 Gingerbread running sweet and as stated above "no" it did not re lock my phone.
A bit more research on the subject reavealed that unlocking is fairly wasy to do anyway - "theres an app for that" :)