I am a total iphone newbie ...
I did not find this info on a forum search....
Please excuse me if I missed it..

I just purchased a used unlocked 2g .... and it works great great on the T-Mobile simm.
It has been upgraded to 3.0 software & UNLOCKED

So how do I know what method was used to un-locked this phone?

Is there an "input code" that gives info from the iphone ...
that will verify how it is unlocked?
Or an icon that will give me a hint of how it was unlocked?

I assume this info will effect how I deal with future updates?

Thanks in advance
Tony

Most of the iphones are unlocked through the use of the dev-team tools. If you have a 2G you probably are using BootNeuter for the unlock.

There is no icon or pin you can insert in order to check what was the program used but with 99% sure it was Bootneuter.

> I assume this info will effect how I deal with future updates?

No, it does not matter how it was unlocked, you can relock it by reinstalling FW 3.0, and then unlock it with redsn0w and Ultrasn0w

If it was unlocked with Ultrasnow, you can tell by going to Cydia/manage sources.. if you see repo666.ultrasn0w.com, it was unlocked with current Dev team tools, Red and Ultra Sn0w. These are compatible specifically with Firmware 3.0, and can be used to unlock your 2G as well as 3G and 3GS iphones regardless of previous unlock or FW used, as long as you dont update to FW 3.1 by mistake, then youre screwed.

to protect you unlock into the future, I suggest you go to iclarified,
iClarified - iPhone - How to Unlock/Jailbreak Your iPhone 2G on OS 3.0 Using RedSn0w (Mac)
follow one of the tutorials there, which will teach you how to save a copy of FW 3.0 on your computer, so you wont be dependent on Apple, or vulnerable to their Firmware Updates..

Just dont install any other version than FW 3.0, an you can keep your phone unlocked..

ultrasn0w is for the unlock of 3G. You have a 2G so you must be unlocked with BootNeuter.

Apple stoped developing the Baseband of the 2G more than 1 year ago, so you can always update to 3.0 and use bootneuter (already packaged inside redsn0w).

Before every update check this forum or the dev-team blog to see if it is safe to update.