Remember Sony's sugar high from a few years back? Sony has been trying to get electric results from glucose-based batteries for some time. But with the competition showing off cool concepts like Coke-powered phones, Sony's Bio Battery program brought its latest development to Eco-Products 2011 in Tokyo. This info just might be worth the paper it's printed on because, well, the battery runs on paper. By using the enzyme cellulase, the device can break down the glucose from cellulose-rich paper or cardboard, which generates enough energy to run a small fan. It's not quite ready for prime time, but given the potential of easily turning junk mail into electricity at a more portable scale, this is certainly worth a continued look.