Unlocked Default – This controls how your iDevice will be set when it is in the Unlocked state. This is the state where your iDevice is in when you are using it. I’ll suggest you should set this to 3G.
Locked Default – This controls how your iDevice will be set when it is in the Locked state. This is the state where your iDevice is in when it’s locked (screen off, or on the Lockscreen). I’ll suggest you set it to EDGE (in Europe and Asia 2G/GPRS).
Charging default – This controls how your iDevice will be set when it is Charging. I’ll suggest setting it on WiFi, when you always charge at home or at work (when you have a working WiFi connection). Note: When you use a ZAGGsparq, a Mophie Juice Pack (air), any other portable charging device, or when you charge at places that have no working WiFi connection, you should set it to No Preference.
WiFi default – This controls how your iDevice is set when it is connected to a WiFi signal. This is the real battery saver. I’ll strongly recommend setting it to Radios Off (>= iOS 3.2 only).
Timeout – This is the time the app waits before switching to a different mode. Leave this setting on 30 seconds when you don’t have coverage issues (outside USA and third-world countries). When you do have coverage issues (USA and third-world countries), I’ll suggest setting it to 1 minute.
Application White List – Applications that are enabled in this list, will prevent Auto3G from switching networks, while they are active. This is especially useful for Online Radio, Music Streaming and Monitoring apps. You should enable any app in that list that fits the previous description.