Samsung has developed a new technology that will allow using water as "fuel" for your phones, i.e. a water-powered battery.
Here's how it works: water contacts a metal plate - this will create hydrogen. Then hydrogen goes into a fuel cell, where it reacts with oxygen and generates electrical energy. This reaction can generate up to 3 watts of power, which is enough for a cell phone. Currently after approximately 10 hours the metal cartridge has to be hanged, but future upgrades to this technology will rid users of this necessity.
The first water-powered handsets will appear by 2010.