This is a simple how-to video about unlocking your iPhone 2G using the firmware version 3.1.2.
First, you are instructed to go to Cydia and search for a program called Boot Neuter, which is a program that will unlock your iPhone. When you find this program simply hit "install". The install will take several minutes and will put an icon on your home screen. Once installed, run this from your home screen and phone will be unlocked. Make sure in your phone settings that "unlock" is set to "ON" then tap on flash. Insert your SIM card, restart your phone, and you are ready to go.
If you follow the steps in this video, your iPhone will now be unlocked.