Talking and texting on an iphone?

Is it possible for me to go to radio shack or bestbuy, get a refurbished iphone4, and then just use an app such as pinger for calling and texting? I really want an iphone, but I don't want to be sucked into a 2year or monthly contract.

You could get a refurbished iphone and just pop a pay as you go sim card thats what my boyfriend did. All they do is cut the simcard up until it fits inside the iphone i wouldnt recommend doing it yourself though