How to leave an iPhone before selling?

[arris666]

Hi guys

I have an iPhone 3G running 3.1.2 so it can be unlocked to any network.

I have just recently received my new iPhone 4 as an upgrade and am about to advertise my 3G for sale.

What should I do to ensure all traces of my use is removed, whilst still allowing the next user to run the phone unlocked to Any network?

Is it as simple as restoring using a custom 3.1.2 before saying bye???

[neodude237]

Basically yeah, just restore to a custom 3.1.3 (or stock one and jailbreak with jailbreakme.com), and get ultrasn0w. I'd advise staying away from 4.0 on a 3G, it sucks.