Y'know what someone needs to invent? A solar-powered plant light.
Yes, that sounds stupid. Bear with me for a second. Right now, I'm trying to grow some basil and parsely and thyme and a few other things. The windows in my apartment are located directly above my air conditioners. The plants need to be warm and in sunlight. With my apartment arrangement, this is impossible.
A friend offered to lend me some plant lights. This seems like a good plan, except that using electricity to simulate sunlight four feet away from a window is possibly the dumbest use of fossil fuel ever. So. What I want is a little solar panel that I can stick on the ledge right outside my window. It'll attach to a wire leading in to the plant lights, which will run on the power from the sun. It's the perfect solution.
And, unfortunately, it doesn't seem like anyone is selling this. (I can, however, buy a backpack with a solar panel on the back, so it'll store energy while the wearer is hiking, and then be used to power little things while camping. Which does seem very cool, but not what I'm looking for.)
t edit: it looks like I can cobble together a system to do pretty much what I want to do from various parts, but it'll be pricy and I'm not sure it'll do what I want it to. I need to review the electricity sections of physics before I try to put together different parts like that.