So, I have a 3Gs with 3.1.3, with I jailbroke with jbm.com. Works great, couple crashes, but good NTL. I really like sbsettings, and backgrounder, some these, etc. BUUUT, I have to test a couple new applications, and they require 4.1 Cannot get them to run on 3.1.3 at all (I really hate how companies are doing this even the one which aren't really leveraging the multitasking to its fullest) I have to do an upgrade, but would like to be able to come back to 3.1.3 if I need to/want to in the future. If say, the battery life gets really poor, or things are so, or I really miss the jailbroken aspect of the phone. Is there a way to do this? Is there a way to create some form of seperate backup of THIS CONFIGURATION in itunes prior to upgrade? What must one do in advance of upgrade a jailbroken phone? I have the customized folders, lots of apps in them, do they need to be brought out prior to an upgrade? Thanks for any tips on doing this. I'm sure the community has had to deal with this - although a simple search didn't yield any results.