Watch the video and you’ll see how you can charge your phone using your body electricity by making a capacitor using items commonly found in your pocket. You need two silver coins, a paper clip, a piece of paper, your charging cable and of course your phone. The electricity from your body is stored in the capacitor and then sent to the phone to charge it. The coins act as a two plates of a capacitor and the air gap and the paper act as the insulator (dielectric). The paper clip is to connect inside of your usb connector to the outer plate of the capacitor. Have fun! Try it out.
We have no idea how much power this can generate, or whether this would damage your phone but the concept looked like something that would be useful in a real emergency.
Also useful in a power outage is the AA battery-powered charger featured here. This one is from K-Mart and costs $13. I keep one in my purse all the time but it’s a useful resource to store in your Bug-out bag or Shelter-in-Place box.