I would not advise using the iphone.unlock.no method - which, incidently, is the method that I followed. But don't do it like I did it. You'll end up with a not-easily-upgradeable iPhone. The current best method is AnySIM111.
In the words of "geohot" (George Hotz - the 17 year-old who did the iPhone JTAG hack and was in the papers):
http://code.google.com/p/iphone-elite/wiki/manifesto2
<+geohot> the best option now is the new anysim
<+geohot> it doesn't touch the seczone, so your phone will never be bricked
Besides, it's a lot easier to just hack a new 1.1.1 phone using the current method, than it is to downgrade the firmware, unlock and activate, migrate, update, and unlock and activate.
luv, as someone who has hacked their iPhone, I have to say that I am really happy with mine. It works well, life is good. You are on T-Mobile USA? Or someone else?
The iPhone Dev Wiki - a good place for news:
http://iphone.fiveforty.net/wi...ex.php?title=Main_Page
The best forum for iPhone unlocking info:
http://hackint0sh.org/forum/forumdisplay.php?f=123
The current 1.1.1 unlock method:
http://hackint0sh.org/forum/showthread.php?t=12817
I actually think the unlock is pretty funny:
3.1 Slide to reach the emergency dial screen
3.2 enter *#307# and then press call
3.3 Delete the #*307# and then press 0. After that press the call button you are seeing and it will show you the answer/decline buttons.Click answer.
3.4 Press hold now and your phone will start ringing again
3.5 Press Dismiss and your phone will go into the contacts/dial screen
3.6 Press contacts from the bottom bar and add a contact
3.7 Add a contact with a random name and write in "Add newURL": prefs://1F [Thanks idutch for the idea!!]
3.8 Save it and click on the contact's homepage. this will take you straight into the setting menu of the iPhone, and you can take all the time to select a WIFI network!
3.9 Write down the IP address of the iPhone.
3.10 Once the wifi is working, do steps 3.2 ? 3.6 again.
3.11 Give it another name and this time add the address as :
http://jailbreak.toc2rta.com/
3.12 Save the contact.
It might be more comfortable to have a nice GUI for unlocking, but it has to be said that the current method can't be beat for excitement and amusement. You'll definitely feel like you earned your iPhone following this procedure.
If you are going to unlock an iPhone, I would recommend getting one in the next two weeks. There's a rumor - which is likely true - that Apple is readying a new firmware to close this unlock method in the next few weeks. And they are fast at rolling out the new firmware to products in stores.