Originally Posted by RoadMike

Don't be dense...if you have the ability to carry a cell phone while riding, you should. Turn it off if you must, but there is no reason not to carry one if you have one. It goes along with wearing a helmet, carrying ID, and obeying traffic laws. You should just do it because it increases your chances of returning from your ride alive. At the very least establishing a habit of carrying your phone when you ride will give the people who care about you a little peace of mind when you disappear for hours at a time to go riding alone.