Hard reset through hardware keys is so important that it just has to come before the review :P

To perform hard reset, first make sure the phone is power off

1. Press and hold Volume Up, Lock, Call and Hang Up buttons
2. The phone will vibrate and the Samsung logo will appears.
3. Count to 3 and release all buttons (release em approximately when the format screen shows up)

There you go :D

There's an alternative you could punch into the phone,

Caution though, this keycode format the phone, including the 8GB internal storage, right away without any prompt!