Every Monday I feed a little rabbit to my carnivorous computer

It is exciting, albeit horrifying at times, to see the servos grab their prey and slowly pull it into the microbial fuel cell. The PC is powered entirely by the electrical energy gained from the biomass.
I try to keep my little girl, age 1.5, away from the scene - not only because the impressions might be disturbing to her, but also for her own safety.
You are right, you cant get that horrific machine at your local gadget-dealer, yet. But the idea of carnivorous robots is not that far from reality.
The design duo James Auger and Jimmy Loizeau has developed some prototypes of bio-energy powered devices like a watch, feeding from flies it catches with a sticky tape or a machine stealing flies from a spider's web. They call them Carnivorous Domestic Entertainment Robots.
These guys might be creative, but they are definitely nuts. Or as the Treehuggers write in their review "Brilliant - completely disgusting, but brilliant!" Yep.