ok, so now that I have the iPhone 4, I'm going to be selling my 3GS soon. I want to unlock it so that the value can go up a little bit, but my question is this - since there is not a working sim card in it, how can I clear all my info from the phone (photos, contacts, music, apps, etc) without iTunes locking it to the "Connect to iTunes" screen? This way I can clear it and still be able to jailbreak/unlock the device. And about how much could I ask for it? Perfect condition, black, 16GB and a few cases - once unlocked I was thinking $300, is that about average? Thanks in advance.