They say that leaves don't grow on trees, and they're right: leaves grow in labs. Labs at MIT, where some exceptionally clever biochemists have reinvented the ol' tree finger and turned it into something that's useful for more than something to keep giraffes in business: this artificial leaf can take sunlight and convert it straight into hydrogen and oxygen.
The leaf in the above picture is able to perform the same trick as real leaves (the kind from plants) do: using just sunlight, it can split dihydrogen monoxide into a couple of H's and an O. You can drop this thing into some water and take it outside, and it'll happily bubble away, giving off pure oxygen from one side and pure hydrogen from another.
This is not the first artificial leaf, but what makes it special is that it's much, much cheaper than anything that's been produced so far. Instead of using platinum as a catalyst to split off hydrogen, the MIT leaf uses a nickel-molybdenum-zinc compound, with cobalt on the other side to produce oxygen, all of which are metals that are fairly common on Earth.
The MIT researchers say that this could be a great way to deliver inexpensive and self-contained sources of energy to the developing world, but to get all selfish for a second, we're excited that this may provide a way to make hydrogen a viable fuel for everything from next-gen cars to fuel cell electronics. In fact, damn the giraffes, let's just start planting these things instead.