We have just finished an iPad deployment project for one of our customers that had a specific requirement. The 90 iPads needed to be restored to a predefined state, once every two weeks, for the foreseeable future.
To achieve this, we had to ensure that they did not attempt to update their backups each time they are connected to iTunes. Otherwise, the next time one of the iPads was connected, the backup would have been updated with the newer settings.
So to stop iTunes running an automatic backup when you plug in an iOS device quit iTunes, launch terminal and type in the following command:
defaults write com.apple.iTunes AutomaticDeviceBackupsDisabled -bool true
To stop iTunes running any backups at all (even manually, or before a restore) quit iTunes, launch terminal and type in the following command:
defaults write com.apple.iTunes DeviceBackupsDisabled -bool true
To undo the above commands, quit iTunes, launch terminal and type in the following commands:
defaults delete com.apple.iTunes AutomaticDeviceBackupsDisabled
defaults delete com.apple.iTunes DeviceBackupsDisabled