hi, i have an english iphone 3g in canada. it has just been sent to me and i think it was jail broken, i managed to plug it into my Pc (vista) and in a moment of madness pressed restore!!!! now when i turn the phone on all i get is a message saying " No sim card installed insert a vails sim with no pin lock to activate iphone". the only sim i have is a Fido sim, is there any way i can get out if this even if just back to the normal os system??

You can jailbreak and hacktivate on a 3G running OS 3.1.3 with redsn0w 0.9.2

see iClarified - iPhone - How to Jailbreak Your iPhone 3G on OS 3.1.2, 3.1.3 Using RedSn0w (Windows) for details

Unlock is not possible because you have restored to OS 3.1.3 but you can use it like an iPod touch (everything else besides the actual making phone calls and sending text messages will work)

I'm jailbroken on 3.1.2 (downgraded since March from 3.1.3) but locked on 5.12.01. Once an unlock comes out for 5.12.01, I'm going to try to use it. I have my AT&T sim from back when I bought the phone in November but of course I canceled the contract back in December. Is my AT&T sim still "valid" for purposes of the unlocking procedure?

Originally Posted by Papuasblya

I'm jailbroken on 3.1.2 (downgraded since March from 3.1.3) but locked on 5.12.01. Once an unlock comes out for 5.12.01, I'm going to try to use it. I have my AT&T sim from back when I bought the phone in November but of course I canceled the contract back in December. Is my AT&T sim still "valid" for purposes of the unlocking procedure?

It should still be valid to get you past the "slide for emergency call" screen so you can jailbreak with Spirit. It will not "unlock" your iPhone. You need an updated unofficial unlock from the devteam (which is coming) for that.