I can’t even imagine how many people plug in their cell phones just before turning in to bed, to leave it to charge overnight (including me, ugh!).  Imagine the energy saved in the world if everyone unplugged their cell phone as soon as it is charged, take the charger out of the electric socket, and then turned your cell phone off overnight.  Seems somewhat small for one person, but multiply that by even a fraction of the 300+ million mobile phone subscribers in the US alone, and a difference it could make.