Tap Emergency Power from a Phone Line
Make Magazine's Jason Poel Smith demonstrates this nifty hack to tap into the power of a phone line. Even during blackouts, there is a small amount of power that flows through some traditional land lines, which is maintained independently of the electric company. Smith shows how manipulate RJ11 wiring with a voltage regulator circuit so that a smartphone can safely access some of that power to make an emergency call. Pocket this one under "MacGyver plot devices," Hollywood screenwriters.