Your urine may be of more use kept about your person. At least, that’s what a team of researchers from the University of the West of England think, because they’ve made a pair of socks that use the liquid to generate electricity.
The first I remember to suggest such technology was the stillsuit in Dune. Which brings up the point that this could be beneficial for travel in places such as space. Electricity doesn’t do much good in the desert 😉
…and wearable charging technology has been talked about for a while, with respect to supporting our cellphone/mobile and such.