KMAC method of downgrading software from 1.1.1 to 1.0.2
Here are the steps:
1) Make sure you have a copy of the 1.0.2 firmware handy and decrypted
2) Reboot iPhone holding top (power) and home buttons *BUT* release the top button 10 seconds into it (right after the screen goes dark)
3) The iPhone screen will appear to be off, but start iTunes (latest version worked for me on the Mac)
4) Option+Click restore and select the 1.0.2 firmware ipsw
5) The phone will restart and error out at the end, this is expected
6) Shutdown iTunes
7) Launch the latest iNDpendence
8) Jailbreak the phone using a decrypted 1.0.2 (it will flash all sorts of error, but stick with it)
9) Activate the phone
10) It will show the SIM error but you should be able to get back in