|Your pee is a goal just waiting to be scored!|
(I took this picture in the Schweiz back in 2006)
Nevertheless, it appears that urine is even more powerful and valuable than I imagined. You can check out this article on Gizmodo if you don't believe me; basically, a few teenage girls from Nigeria have created a generator that runs on urine. You can check out the link or their references yourself, but I think the take-home message here is abundantly clear:
Keep those empty pop bottles handy, since it's time to start hoarding your urine!