I restored my phone to 1.1.1 before and did it again through iTune.

Second time around, the phone was already unlocked and I didn't need to use AnySim.

So is Restore function in iTune just a reintallation the OS, or does it format completely then install OS.

Just curious cuz i am upgrading to 1.1.2 soon and was thinking of going with fresh install to avoid any weirdness in the future.