Anda and I have spent a lot of time over the years dreaming up ways people could harness "people energy" to make electricity for their homes.
Things we've thought of:
Mini solar panels that charge just one lightbulb, mounted around the house on the outside or on the roof. The technology exists, but it's used for shoplights and for camping bulbs (or lights used in rural third-world areas). I'd like to make some can lights that mount into an outside wall near the roof line, with the solar panel on the outside of the wall. I'd put a line of them all across the living room wall and use them in addition to regular lights. You'd have to wire them to a light switch, but that shouldn't be too hard since those camping lights and shed lights have switches. Each bulb would have a battery that charged through the day and lighted the bulb at night--the bulbs aren't particularly bright, but a bunch of them would be fine.
Moving water. Lots of water moves into, around, and out of the house. There should be a way to harness that moving water energy on a micro scale to produce power. Like, Anda said, why not a little generator that makes a bit of electricity when the toilet flushes and fills (on the clean water end, of course). Or on the water main--they already have a meter there. Why not make the meter also a mini generator/battery charging kit?
Walking around. Anda says why not pressure plates under flooring and on stairs to use the impact energy to convert to useful power for the house? They're doing this under a road in the Netherlands. Why not on a micro scale in your house?
There is a lot of thermal energy in houses. Why not put in a passive attic fan--the kind that vents heat out in the summer (these are all over in Las Vegas)--and capture the energy of the heat rising out of the attic?
Also, recycling heat. We are constantly venting heat off things--back of the fridge, back of the air conditioner, off the processors in computers. We wondered why we don't find a way to capture that heat (especially since it's the form of moving air a lot of times) to "repay" the cost of venting it (running the fans that get it off the machines).
None of these would make a lot of power. Nothing worth any money commercially. But the idea we have is that each house might be able to collect enough little sources of power to make their own energy, at least in part, supplemented by the power company. So the power company powers your fridge and computer, but you charge your phone and run all your lights from energy you make yourself.
Most of these are not possible for us to make ourselves, so we just keep dreaming. But if I ever buy a new house or have money for remodeling, I'm totally going to make the can lights that are wired to mini solar panels outside. That will be so easy.