Erase data on jailbroken and unlocked 3GS

[quiksilver1209]

Sorry I am new to the boards and need some help

I got my new iphone 4 yesterday and have my old 3GS unlocked and jailbroken on 3.1.3 sadly on Spirit.

I am preparing to sell the phone and would like to keep both jailbrake and unlocked, how can i go about clearing out most of my personal data if possible?


Also my sister wasn't thinking yesterday when she got her new iphone 4, and erased and content and settings with her 3GS. By doing that, does that restore it back to factory settings thus losing her jailbrake? Also since the 3GS isnt activated anymore is there a way to activate it again so i can possibly jailbreak it again?

 

[Applejuiced]

If you do tha erase all content and settings you will lose your unlock and JB and be forced to restore to 4.0
Unless you have your SHSH's saved then you could downgrade to earlier firmware and JB and unlock again.
Its not simple.
You can activate any iphone 3GS with a valid AT&T sim but wont be able to JB or unlock it on 4.0