Other than your usual SIM card unlock the only place to get an officially unlocked iPhone is through Hong Kong and parts of Europe. Unfortunately for those who spent untold amounts of money to get an unlocked iPhone 3G, your efforts may all go to waste. The new iPhone firmware 2.2 is reportedly re-locking those unlocked iPhones.
Users in the Apple support forums are saying that if you purchase a legally unlocked iPhone and then updated it in another country the device may become locked. “I bought my iPhone 3G legally unlocked from HK, and I just upgraded to iPhone 2.2, but it seems my phone is locked now. On the phone it says emergency calls only and iTunes is saying not supported SIM.”
If you have an unlocked iPhone and have not yet upgraded to the iPhone firmware 2.2 we suggest holding off just in case this ends up being true. You don’t want all that hard earned cash going for nothing. If you simply can’t wait for the update, try getting your hands on the update from the country your iPhone came from.