Interesting as you don't have to mess around with a soldering iron to do this unlock, but it will only
work for AT&T network versions (the only ones currently available in the world anyway) being unlocked for Orange UK, and is highly unlikely to work when the iPhone is released exclusive to o2 this Christmas in the UK (Apple are already hard at work resolving the flaws that unlockers have so far managed to exploit, and they themselves are VERY few and far between lol).
It has apparently only been done successfully on Orange by anyone in the UK, so it is unknown as to whether or not it can work on any other networks, and is therefore not advisable to be tried on any other network.
Also, you do it at your own risk. There is a possibility the phone can be broken.
The only other unlock I know of can work on any network, but requires physical changes to the phone hardware itself, and also requires the sim to be programmed to work on the phone. And is basically a complete pain in the arse to do.
Personally, fook the iPhone, its shite, but someone may be interested in it hehe.