Comment T-Mobile International is the Ticket (Score 3, Informative) 176
My father has been deployed to Iraq, Afghanistan and other places around the world and he brings with him a T-Mobile Quad-band phone with the International Package. He got pretty good service in Afghanistan. You can check the rates here: https://www.t-mobile.com/International/RoamingOverview.aspx?tp=Inl_Tab_RoamWorldwide
It looks like calls are about $4.99/minute there, so you probably won't want to chat for hours on end, but my family has used this method for several deployments and it works stellar. Thank you for your service.