Is it possible to return the iPhone to its very original factory state?
Back to the screen that asks for SIM insertion and iTunes connection on background. Is it?
Settings -> General -> Reset -> 'Erase all Content and Settings'. On some devices (3gs and 4) this will only return the iPhone to factory settings (but not activation mode). For the latter, I'd just plug it in to iTunes and click 'Restore'.
If I understand what you mean is restoring to its original state -
- Connect iPhone to the computer.
- In
iTunes, under theDevices, select your iPhone. - Select the
Summarytab across the top. - Click
Restore.