I have wifi at the house, but I really need cell/data service at and around my house, for things like walking the dog, bike rides, etc... Is there a way to force calls to go over skype instead of celluar, but have it be seamless?

Plus if the car ever broke down on that stretch of road when I was alone with my little kids , it would suck not having a cell phone.

Edit: I think my previous post made it sound like just 3G/edge didn't come in, but I lose cellular as well.