before you start you will need SB Settings and you can find it in cydia/rock
These are instructions on how to block and disable Edge and 3G data usage on your iPhone using the SBSettings Data toggle.
Press to launch Cydia from your iPhone Springboard.
Select SBSettings Addons from the list of Sections
Choose Data Toggle from the list of Packages.
Press the Install button at the top right of the screen.
Press the Confirm button to begin installation.
Once installation has completed successfully press the large Restart Springboard button.
Swipe your finger across the status bar to pull up the SBSettings menu
Press the Data toggle to deactivate data.
You will notice the icon goes red and your IP Address changes to 184.108.40.206.
Edge and 3G data access on your device is now blocked.