We've discussed similar products like this before, but these firefly jars are so extremely easy to make! I'm not entirely sure how much light they actually emit, but this would be such a cool alternative to patio lights.
All you have to do is find some mason jars, and flick some glow-in-the-dark paint in the jars, let them charge in the sun during the day, and voila! Glowing lanterns at night.
I did some research and apparently there are some non-toxic glow-in-the-dark paints out there. I would hope that they have a fairly low environmental impact as well.
Related Post: Set the Mood: Our Favorite Outdoor Lights Under $100
(image: We Heart It)
8 Secret Spots to Hide Valuables at Home
The Live/Work Studio of Robert Siegel Handmade Ceramics
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
Howard Butcher Bloc...
10 Easy Vacation Meals to Feed a Crowd
Recipe: Chopped Brown Rice Salad with Grapes and Pecans
Very cute idea but the charge would be gone before it was even fully dark out. Short of having an led in it or a blacklight nearby this won't do much at all.
It's a one shot deal, but you could get more light out of cutting open some glow sticks and flicking them around the inside of the jar. Would last most of the night. Still not putting off much light though.
I am absolutely in love with this idea. This is my afternoon tomorrow.
oh jmorri26, glowsticks! I have bunches of those! I think we may have to do this tonight!!
I think you could charge them inside the house, right? Love these!
The glow-in-the-dark paint we have lasts quite a while.
IDK what is inside a glow stick but I would be very careful with that stuff around kids.
My daughter wants to put the fireflys in the jar with the glow-in-the-dark paint. I am thinking we could paint the outside maybe...