Familiarity breeds contempt. While a cell phone may be a supplement to your survival kit (as it is mine), by bringing it into the discussion as standard emergency equipment, use of the cell phone will inevitably morph into being primary emergency equipment and other gear will be left behind. People will start carrying two cell-phones so they have a back-up. The goal is to teach self-reliance and responsibility -- not how to exceed your limitations and still survive by the grace of Verizon.