What happens if i update my unlocked/jailbroken iphone to 3.0?

It is going to erase the entire OS on the phone. This will undo your jailbreaking or unlocking. Your notes and contacts might be safe, but most everything else will be gone. If you are using it on a network other than AT&T you will lose the phone part. (assuming you are in the United states)

Really, just wait a few days.

Steve Jobs will hunt you down and force you to buy an iCube.

@johnpowell I’m fine if I lose everything including the phone part (seeing as I’m living on an island with no service), but previously when I’ve had locked iPhones they will check the SIM card, tell me it’s not AT&T and the phone will be locked except for emergency calls.