T-mobile has just released a new technology where your cell phone can switch over to wifi automatically when it senses it in range. They have a new plan where you can get unlimited minutes in a wifi spot for $10 a month as the introductory rate. This means that when you make calls from a wifi spot it won't count against your minutes. As of today, the service is available nationally. This also would make calls based out of your home, if you have wifi, totally free. So check it out, it might save you some dough.