I just got the Iphone 4 today, and I'm going to sell my 3GS to a friend. I have not jailbroken the ip4 yet though. First off, what is the easiest way to erase the 3GS to get all my info off of it, but still maintain the jailbreak and unlock on it? Next, how do I get all my contacts, apps, mp3s, etc onto my ip4? Should I jailbreak it, and then simply sync with Itunes, or should I restore from the backup I created for the 3GS?