Originally Posted by regression
Google Voice by itself will use your minutes.
Some people around it if they already have VOIP service. Also, if you have free calling to / from a number (like some sort of friends & family plan), you can add your GV number to your list of free number. Then, you will have to get a special dialer to act as a calling card to dial your GV number.
This document goes into it in great detail:
Unlimited Free Calling with Google Voice - Google Docs
Actually, you don't need anything special. I have GV, and "favorite 3" (or whatever it is called with Sprint) and made my GV number one of them. So, when I need to call a land line, I just call my GV number from my phone's dialer, (I have a speed dial set up for it). Then when the call is connected, GV answers, and one of the options is push 2 to make a call. I then enter the phone number I want to call followed by #, and the call is connected. Minutes are not counted.
I can give out my GV number to anyone that might call me from a land line, and GV is set to forward that caller to my cell. Slick. There are many other features of GV, but this is how I use it to avoid using minutes. The GV app will not work with this, as it is known to dial (sometimes) random numbers, rather than the one you picked when you signed up with GV. (That may not make sense, but trust me for now)