Personal Data Wipe while keeping Jailbreak

[phoenix1492]

I'm in the process of selling my 'old' iPhone 3Gs 32GB on craigslist and getting the new 4G model. What can I do in order to delete all my personal data (pictures, calendar, contacts, notes....etc.) off the phone while still keeping the jailbreak ?
Currently i'm at OS 3.1.2

Thanks Guys!

p.s. if you could recomment what jailbreak to use redsn0w or blackra1n i would greatly appreciate that. i'm pretty tech savy, but the whole jailbreak process is still somewhat new to me.

 

[GraphicsGeek]

Completely wipe it, then restore and rejailbreak. Ive done this for the past 3 iphone before selling them on ebay.

 

[Bakakage]

Do you have your 3.1.2 SHSHs saved? And do you have the old bootrom?

 

[phoenix1492]

Do you have your 3.1.2 SHSHs saved? And do you have the old bootrom?

I don't know if I do...I have an old backup saved.