I previously wrote about using Gizmo Voice to integrate your Gizmo and Google Voice accounts for free incoming and outgoing calls. Unfortunately, Gizmo voice is no longer completely free. Incoming calls are still free, as before. Outgoing domestic calls are free during the first three minutes, after which you will be charged $0.02 per minute.
You can still make free calls by using the Google Voice web interface or DialCentral on your N810. In Google Voice, click “Call” in the upper left. Enter the phone number you want to call. Under “Phone to Ring,” select which of your forwarding phones you want to use for the call. Google Voice will ring that phone. When you answer, it will ring the number you are calling. Gizmo will consider this an incoming call, so you will not be charged.