Some info on Firmware 1.1.2:
Many of you who have 1.1.1 probably think that it is perfect and updating to 1.1.2 is unnecessary. I used to think the same way. Let me just dispel all rumors and say that 1.1.2 is a lot better than you think. Here are the three main reasons why:
- It has improved stability. Much less crashing.
- It has increased CPU speed. When programs open and close, the window no longer "skips" but smoothly opens and closes like it should.
- It has improved battery management. This means your battery life will be improved.
For these reasons, I decided to write this guide.
BEFORE YOU BEGIN: - This will not work if you the if 4th and 5th digit of your serial number is 46 or higher. In other words, if you bought your iPhone and it already came with firmware 1.1.2, then this guide will not work! Out-of-box 1.1.2 iPhones are currently (as of 11-29-07) impossible to unlock, so don't try.
- Before you do this, go to Settings > General > About. Make sure your firmware version is 1.1.1 and your Modem Firmware is 04.01.13_G.
- On the other hand, if everything on your iPhone checks out, don't be nervous. This unlock will be very easy for you. I just have to weed out the newbies who don't know how to focus by using lots of red bold print

NEEDED:
- 1.1.1 iPhone, possibly previously unlocked with anySIM 1.1.
- The iPhone Dev Team's 1.1.2 Jailbreak Program HERE.
- WiFi/EDGE access on the phone.
- iTunes (the computer version)
STEPS:
1. Go to Installer (make sure it's the newest version), then push the Install tab on the bottom, go to All Packages and install
Oktoprep. I must stress the importance of this step. If you forget to do this step and update to 1.1.2 first, then you are going to have to downgrade back down to 1.1.1 again, which is a headache.
2. Open iTunes on the computer, sync your phone, then update your phone to version 1.1.2. If a newer version is out by the time you read this guide, do not use that version. Only
1.1.2.
3. iTunes will now possibly encounter an error, your phone will be unactivated and will inform you that you have an incorrect SIM. Do not panic. Go
here and download the 1.1.2 jailbreak program by the iPhone Dev Team and run it. It will take a little bit, just let it completely finish. When it's done, you will have the friendly "Slide to Unlock" screen on your iPhone and you will be taken to the homescreen with the Installer app waiting for you.
4. Now push Installer, go to Install on the bottom, then All Packages, then find and install
anySIM 1.2.1u. Watch out my friends, because
there will be several anySIM versions to choose from, many being version 1.1, which will not work. Just check the version before you install it, and make sure it says 1.2.1u. (If for some reason anySIM 1.2.1u isn't on the list, then go to Sources on the bottom, then Edit, then Add, then type it
rep.frenchiphone.com, then Refresh, then Install, then All Packages, then anySIM 1.2.1u.)
5. Once it's installed, go into Settings and turn Airplane Mode ON. Don't forget this step! If you do, anySIM 1.2.1u will fail and who knows what will happen then. Also, go to General > Auto-lock and make sure it's set to Never.
6. Now fearlessly run anySIM 1.2.1u. Once it's done, turn Airplane Mode OFF, and watch the signal bars appear! Feel free to uninstall anySIM as it is no longer needed.
BONUS STEP FOR THOSE OUTSIDE U.S.: Your phone won't work until you go into Installer, then All Packages, install iWorld, and pick your country.
Did something go wrong? Go here and follow instructions to get back to version 1.1.1.
Please give me feedback on this guide so I can improve it if needs be.
Special thanks to Sassha who wrote this guide first.