This might be a dumb question, but I'm really new at all this. I just successfully downgraded from 4.0.2 to 4.0.1 and was able to jailbreak and unlock my 3gs using jailbreakme. As far as I know this phone had never been jailbroken before.
My previous iPhone was water damaged recently, and when I plug the phone in I am given 2 options in iTunes:
An iPhone has been previously synced with this computer
Set up as a new phone
Restore from a backup of "Old iPhone"
I don't risk losing my jailbreak or unlock by restoring from my old 3G backup do I? Will it bring all my contacts/apps etc back?
Excellent. It's weird, all of my music is now on the new phone, as well as my recent call history from before the old phone broke, but none of my contacts or apps transferred on? Any way to get those back?
You can do that from iTunes. iTunes syncs those according to your preferences, so you can find that on your iPhone page in iTunes, looking through the tabs.