What exactly does this do? Does it just pretty much wipe ALL your data off your phone? Is this the most secure way of deleting everything?? Reason I ask is because even though I don't want to I might plan on selling my 16GB/3G to cover the cost of my 3Gs. If I do this will the person that bought it be able to use it as an iPod touch or phone/jailbreak or whatever and unlock? I am clueless about this option please help me and fill me in.