How to Jailbreak an iPhone 3G or iTouch 2G 4.0 / 4.0.1
As of today, there are no legal barriers standing between you and jailbreaking your iPhone, iPad, or other mobile device. Hooray! If you were afraid of Apple coming to your house at night if you jailbroke your phone, you can finally let go of the fear and make your iDevice the beast it should have been all along! This video will show you how to jailbreak a iPhone 3G or iTouch 2G with iOS version 4.0 or 4.0.1 using Redsn0w. Now you can fully enjoy your Apple device.
From the creator:
HELPFUL TIP - If You're IPSW Is Saved As A .Zip , Simply Delete The .Zip At The End To Turn It Into A Regular IPSW.
After You Update Or Restore And See The iTunes Logo, Do Not Panic But Simply Close iTunes And Run The Redsn0w Which Will Resolve This Issue By Hacktivating Your iPhone.
Run Redsn0w as Adminstrator, and Select 4.0 Official Firmware
If You Get Stuck At "Waiting To Reboot" Then Either You Have An MC Model, Settings - General - About - And Your Model Number Starts With MC. Or You Are Not Holding The Home Button Long Enough During The Jailbreak.
To Get The Edit Cellular Data Network Tab Back You Will Need To Restore From Backup In Itunes By Right Clicking On Your iPhone Tab And Select " Restore From Backup " Also Select The Backup From Before 4.0
For APN and MMS Settings Go Here : http://everythingapplepro.blogspot.com