Saving contacts

[MacPro23]

I jailbroke my iPhone 4 a couple months ago. I would like to restore and erase everything on my phone but the only thing I want to save is my contacts. How to I unjailbreak it and erase everything but save the contacts? Thanks.

 

[PNutts]

You may sync your contacts to your computer, Yahoo! mail, Google mail, MobleMe, etc. to preserve them and then sync them back.

http://support.apple.com/kb/ht1386

http://support.apple.com/kb/HT1296