How do I restore a jailbroken iPhone 3G?

Question

How do I restore to the normal non jailbroken state my jailbroken iphone 3G? Is there any permanent change when you jailbreak it?

Answer 1

All you need to do is plug your iPhone into iTunes, click on it under Devices:

And click "Restore":

iTunes will make sure that you do actually want to restore:

Jailbreaking does not make any permanent changes; a restore will put your iPhone back exactly the way it was before you jailbroke it.

Answer 2

There aren't any permanent changes made to your iPhone when JailBreaking. All you need to do is plug it into your computer, open up iTunes, and update/restore iOS normally. This will return it to a fully working, non-jailbroken state.