It’s pretty simple to downgrade your iphone to 1.1.1
A/ Put your iPhone on DFU mode (using Ziphone)
B/ In iTunes hold the shift key and click on ‘Restore’
C/ Pick the 1.1.1 firmware file on your computer (if you don’t have it, download 1.1.1 iphone firmware) and press ok
D/After about 4 minutes you will get an error (That’s OK)
E/ Close iTunes
F/ Download Iphuc
G/ Type each of these commands on their own line and hit enter for each:
cmd setenv auto-boot true
H/ Wait a few seconds and your iPhone should be out of DFU mode and at the activation screen.
Put iPhone in DFU mode: With iTunes still open and the iPhone still connected, press and hold the Sleep/Wake button and the Home button until the screen turns black. Once it does, let go of the Sleep/Wake button. Continue to hold the Home button until iTunes displays a pop up about the iPhone being in recovery mode. Click OK.
If you want to make phone calls through VoIP, check out : sip.free.fr
It is an easy way to make phone calls trhough VoIP.
To use it, you need a jailbreaked 1.1.2. or 1.1.3. iphone!
It will be available soon to all iphone users worldwide
The Apple iphone 1.1.3. firmware has been jailbreaked.
You can get more info on: Ziphone
To do so, you don’t need to downgrade you iphone!
It seems to be the easiest way to jailbreak your iphone!
Disclaimer: My Gadget Info is not responsible for any accidental damage that may ensue should something go wrong in this procedure. However, I can tell you that I have performed this operation multiple times with no failure, and that a simple restore in iTunes will bring your device back to factory settings. Also, should you need to bring in your device to the Apple Store or Genius Bar, it’d be wise to restore it before because loading 3rd party software on the iPhone or iPod touch does void your warranty.