Hard Reset of the T-Mobile G1

1. Power off the G1
2. Hold Home Key + End key for 20 seconds or until you see a "triangle with an exclamation point and a picture of the G1"
3. Open the QWERTY keyboard and hit Alt+W
4. Restored!

Soft Reset of the T-Mobile G1

1. Power off the G1
2. Hold Home Key + End key for 20 seconds or until you see a "triangle with an exclamation point and a picture of the G1"
3. Press the home and back buttons