Have you ever wanted a portable, eco-friendly gadget charger or battery? Something to take to the beach, on long flights, on roadtrips, to Disneyland, to Everest? Something that relies on readily-available materials, and is fast and effective?
If yes: Excellent! Read further.
If no: Too bad, because I'm telling you about it anyway.
Horizon Fuel Cell Technologies will be releasing its portable hydrogen cells and charger sometime this year.* The Hydrofill still uses standard electrical outlets (or solar panels) to generate and store the hydrogen, but after that, the energy can be taken anywhere, safely.
All well and good, but how does the Hydrofill generate hydrogen? By breaking down water you pour inside it. That simple.
If you need more energy than these fuel cells can provide, there's always the Backpack Power Plant produced by Bourne Energy**, which uses river currents, or the Sun Catalytix system, which is another just-add-water one. That's in addition to the other proposals using ocean*** or river currents, which I'd definitely like to see soon.
Those aren't the cool proposals though. The really interesting water-to-electricity proposal has to do with leaves—and I don't mean these ones. It turns out that, if you use wafers of glass to build leaves with water-filled "veins" inside them, you can use the evaporation of the water to not only draw more water into the veins, as per nature, but also to generate electricity****. It's more of a supplementary technology, as it generates nothing close to hydrogen cells or solar panels, but unlike the hydrogen cells, this technology doesn't destroy water, so the same 6 L (or whatever) can be reused.
This has phenomenal potential for aesthetic power options, of course. You wouldn't need to stop with leaves or a small "plant" as my sources point out. You could have trees! Gardens! Forests! Right in the middle of a city, like an powerplant version of Central Park! Or you could move away from plant appearances and build a house of this material. (It would almost definitely need to be opaque glass.) I'm betting you could even take this technology into space without too many, if any, adaptations.
I won't try to build a world based on this tech (as always, too many variables), but I can tell you it will be pretty. Very, very pretty.
* Engadget and BoingBoing, with a short video here
**** Engadget. Also, that's a NewScientist link again, so I can't quote it even though I want to. Bah.*****
***** Yes, I know I'm being passive-aggressive.