Yes, it works, I succesfully managed to do it myself and to a friends iPhone.
Here's the method I used...
Files you'll need before you begin:
iBricker
iPhone 1.1.1 Firmware Version (If this saves as a .zip extension, rename it so that the extension is .ipsw)
iPhone 1.1.2 Jailbreak File
Steps
Make sure that your iPhone is turned off. Now, hold down the Home button on the iPhone and connect the iPhone to your computer. iTunes should now detect that you have an iPhone in restore mode. At this stage you may find that some usb drivers are installed, this is ok. In the iTunes window press and hold the Shift Key if using Windows, or the Apple Key if using a Mac, and press the 'Restore' Button in iTunes. Now go and select the 1.1.1 Firmware that you downloaded earlier and press ok.
We now wait for iTunes to do its stuff and then give a '1015' error.
The iPhone will restart to the 1.1.1 restore screen with the iTunes logo on it. Now quit iTunes.
Windows - Run iBrickr and choose to boot your iPhone. The iPhone will start up now. Now quit iBrickr
Make sure that the original o2 SIM Card that came with the iPhone is currently in the SIM slot of the iPhone
Now press the Home button and you will be at the activate iPhone screen. Slide to make an emergency call. Enter the following *#307# then press Call. The iPhone will ring, press the X button at the top right of the screen to delete all the characters you just entered. Now enter: 0 then press Call again while it is still ringing. Now press Answer, then press hold, then press Decline.
You will now be at the iPhone's dialing keypad. Press the Contacts button below the dialing keypad. You are now at the contacts screen. Press the + in the upper right corner to make a new contact.
Press the big First, Last button. Enter A for the first name then press Save in the top right corner. Now press the Add new URL button. Enter: prefs://1F then press Save in the upper right corner, it will take you back a screen, now add another URL called
http://jailbreakme.com and save this also.
You should now be back at the contact's page, now press Save And click on the prefs://1F url
You will be taken to the Settings menu. We need now to turn the Auto-Lock feature to never. Press General, Auto-Lock and select Never. Now press Settings in the top left hand corner
We now need to Join your Wireless Network. So choose Wi-Fi and choose your network when it appears. Enter your password that is set up to join your existing wireless network and press JOIN
Press the Home button and will be taken back to the activate iPhone screen. Slide the emergency slider again. Enter: 0 then press Call. Press Answer, then hold then Decline.
Now click on contacts tab at the bottom of the screen and select the 'A' contact and head to the jailbreakme.com url. Scroll to the bottom of the page and press the Install AppSnapp button. Safari should crash after a few seconds and take you back to the activation screen
*** Now if Safari does not crash after about 1 minute then press home and go through stage 8 and 9 again. You may need to go through this stage a few times. If Safari freezes then hold in the Home button on the iPhone and this should take you back to the Activation screen and start from stage 8 again. ***
10. The iPhone may do a few different things here. It may freeze and then make a sound. Or it may restart itself. If the phone rings press to answer it. After the iPhone restarts you will know that this stage has worked as you will have access to the iPhone Springboard (Menu)
Now that you have access to the iPhone Menu select Installer. Now select the Install option down the very bottom. Now scroll to iPhone Tweaks 1.1.1, select it and then OkToPrep and install.
After it installs connect your iPhone to your computer and then launch iTunes
Now click on UPDATE in iTunes
Now just wait for iTunes to update your iPhone. This may take a while
After Part 3 is over, close iTunes and then disconnect your iPhone
Reconnect your iPhone to the computer
Now extract the 1.1.2 Jailbreak File to a folder in your computer
After this has been done open up the extracted file and open the Windows.bat file (if Windows) or jailbreak.jar (if Mac)
A command prompt window should open and disappear and a new box should appear. Ensure that 'install ssh' is ticked and click on jailbreak
You should now have a jailbroken iPhone!! Pop in your o2 SIM Card and you should be good to go.
Your Questions
will EDGE work? or is it restricted to GPRS? : I think it does, but I haven't tried it properly yet.
will web browsing work via o2? : Only tested it via WiFi and it works perfectly.
will email be restricted to 02's email? : No
will visual voicemail work? : No
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Hope that helps, if you have any questions, just feel free to ask. It should be fairly straight forward though.
Payment? Yes please!
