Science is wonderful of course, but it can also be vaguely terrifying if you take things to their logical (or not so logical) conclusions. Take batteries that run on human blood:
So scientists have developed a battery that is powered by human blood. The idea is a cybernetic power source, to keep your pacemaker or whatever running. But, lets think about this for a second...what do we have way too much of on this planet? People. And what do we have way too little of? Power. A battery that runs on human blood is an easy fix for both of them. Jonathan Swift would be proud of this, screw eating the poor, lets just power all our gadgets with them.
From the Upcoming ueue, submitted by redsfaithful.
Only a fool who thinks that The Matrix is a documentary could envision enslavement of humans as an energy resource. Ever hear of thermodynamics? You have to put more energy into feeding and maintaining your imagined human batteries than you'd get back - no matter how efficient the technology. And I'll bet the technology isn't very efficient. But I imagine that even an inefficient battery that doesn't require surgical replacement would be very desirable for pacemaker users and other implantable medical devices.
For a number of years I've toyed with the idea of a children's playground wired (safely, of course) to a storage battery. The movement of the equipment, and even the movement of the children's feet on certain surfaces could be converted to electrical energy, just like a windmill generator. For anyone who's wanted to "harness that energy" while watching kids at play...
But that makes me wonder... would having a blood-battery in you make you burn more calories naturally? :P