We can tell you how to rescue a cellphone that's been dunked in the water, but it's a bit more difficult for us to explain how a cellphone can be powered by water. This fuel cell by Japan companies DoCoMo and Aquafairy can recharge a cellphone several times, and it's a quarter of the size and twice as powerful as the methanol fuel cell prototype presented by DoCoMo a year ago.
It's not exactly creating power out of water, but outputs its 2 watts by using Aquafairy's thin film power unit technology, a fuel cartridge that serves as a catalyst for turning water into hydrogen which runs the fuel cell. The thin film unit still needs fuel (what type of fuel isn't mentioned), but it looks like a great storage medium to provide plenty of power on demand—enough to charge your cellphone in the same amount of time it takes when using an AC adapter. Now if they can just bring the cost of this technology down to earth, this could be something useful.
Water Powered Mobile Phones [Cellular News]