Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Put your contacts on iCloud or save your contacts to your address book on your computer. Once you get your phone, sync to those but don't restore from backup.
 
Wirelessly posted

I'm currently jail broken and wanna start fresh

Personally I'd recommend using PhoneCopy (free) from the App Store to back up your contacts on a remote server. Then restore and update to iOS 6 then reinstall PhoneCopy and load your contacts back on :)

That's my personal preference anyway, I'm sure there are various methods other people prefer.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.