I am very new to all of this and have done a million searches. Thanks to this forum I was able to get this far but I am now stuck and could really use some help please. I had my Iphone 3G Jailbroken and Unlocked for T-Mobile on 3.0 using Cydia and Icy. Phone went into DFU mode and was restored, new software was installed. I made a mess of things. Now I want to get it working on T-Mobile again. So far I have sucessfully downgraded the software to 4.0.1 and re-jailbroken it. Now I would like to unlock it again, so I can use it on T-Mobile. From what I can tell I need to downgrade the baseband because it is currently on 05.15.04 but this is where I am lost. Can I do this on the 3G and if so what steps do I take? Thank you so much for any help.