sciencehabit writes: The newest source of battery power for your cell phone is both cheap and abundant. Scientists report that microbial fuel cells using human urine can directly power a cell phone battery. However, the devices are not quite portable enough to come in handy during a marathon pub crawl. One consists of six, 4-inch-long ceramic cylinders; the other is a network of 25 smaller fuel cells borrowed from the team's waste-fueled EcoBot. And urine-powered conversations would have to be short and sweet. After 24 hours of charging, a Samsung phone stayed alive for 25 minutes—enough to send several texts and make a 6-minute, 20-second call.