It's a bit of a misnomer to say that this is the full unlocking process, but this procedure will let you go through most of the T-Mobile G1's features without actually activating a SIM card from T-Mobile. If you're not quite prepared to sign a two-year contract, you can actually use the T-Mobile G1 on Wi-Fi alone. It's a simple five-step process. First, you'll need to borrow an activated T-Mobile SIM card from a friend. Second, go through the setup process to link to your Google account. Third, enable Wi-Fi in the settings. Fourth, connect to a nearby hotspot. Last, remove the SIM and insert the unactivated SIM that came with the G1

1. Go through setup process to link any Gmail account
2. Go to Settings > Wireless Controls > Wi-Fi Settings > Enable Wi-Fi
3. Connect to nearby Wi-Fi network if one is available
4. Remove said SIM card and insert unactivated SIM that came with the G1

Tada! A T-Mobile G1 that does only Wi-Fi! I just wanted to clarify for anyone confused, this is simply a way to get past the initial setup screen when you turn on the phone. If you bought the G1 without signing up for a new 2 year agreement, you got an 'unactivated' SIM as opposed to an 'activated' one with a new 2 year agreement with T-mobile. Unactivated should not be confused with unlocked! There is still no news on unlocking the G1 without T-mobile's help or purchasing an unlock code online. This is only for those of you who need to be able to use the G1 over W-Fi and not make calls. Anyway, calls over Wi-Fi will most likely be an option soon when an app comes out like what happened with the iPhone.