google voice uses your cell plan minutes
at least on at&t it does.
I am usually connected to wi-fi on my android phone, so i figured "use google voice to make calls, free for US calls, right?"
well, after getting a txt from at&t about my talk usage and checking the bill (all plan minutes and rollover minutes used up, with a lot of overage), i called at&t.
the agent i talked to said they are familiar with google voice, and at&t phones will not make voice calls over data connection - 3g or wi-fi.
i did not find reference to this in any of the google voice documentation
at least at&t was good enough to credit my account the overage, and give me some free rollover minutes back after i explained what had happened.
