I saw in Popular Science today that someone (Logitech or Kensington?) has a wireless keyboard with a battery life of three years. Pretty good. And then I thought, why not just use the energy of the person pressing the keys — I’d think there’s enough force applied that it could keep a battery charged for the short bursts of transmissions. Too, why not set a mouse on rollers and use the energy of moving the mouse around? Looks like someone already thought of the mouse.