I have a canadian friend who wants to do the "snowbird thing" and spend his winter months travelling with a camper thru various US states. He would like to use an Iphone in the US for the 6 winter months. He would like to have a voice/data/tethering plan while he travels throughout the USA. Does anybody have any ideas how he would accomplish this, and what kind of short term (6 month) plans or pre-paid options available? Any idea as to the amount of voice/data plans would @ cost? He has a locked canadian iPhone4 at the present moment, would it be able to be un-locked, or jail-broken, and used thru ATT? Thanks for reading and sharing your thoughts on this.