So I think I'm gonna buy one from down under. Does anybody have any experience with the unlock codes and whatnot? Just don't want to end up with another one I can't use.

You cannot buy an iPhone without a contract in Australia - and as yet no matter what country you are in there isn't an 'unlock' available for the 3G iPhone ( I am in Australia)

Now that's just a load of crap, I live in Australia and just purchased a 3G iPhone - without a contract through Telstra for $725 and paid $150 to have it unlocked (by the way had Telstra refund my money for the unlock - do a google search for why).

I can now use any sim card I want and it works. I've tried Virgin and Telstra and both work. I'd call that unlocked...

you can buy a 3g iPhone without a contract in Australia from both optus and telstra. And optus will unlock prepaid ( out of contract iPhones) legally for 80 dollars. Please get the facts straight.
Outright iPhone in Australia cost $850 odd. You can read about the prices all over the net.

Sorry to correct you but you are missleading people.
I also live in Australia.

meh..........

Well I meant I was buying one off of ebay or from somebody down there that has them for sale.

Once they request the unlock I shouldn't have problems right? AUD 1200 kinda sucks though.

You should be able to activate it in iTunes with any SIM if it is officially unlocked.

Ok, thanks.

Title description updated from > Australian iPhone

i bought an italian one unlocked from ebay, activated with a UK orange sim card via itunes, works fine and everything works on it except visual voicemail (but that only works on official apple partners contracts). cost about £650 uk sterling