Interesting idea, obviously clocks have used that form of power for quite a while... I'd have never thought of using it for anything other than a pendulum clock though.

Three months worth of kerosene (or six weeks in the second generation version) is an astronomical investment for a culture who's barely able to meet it's day to day needs. For example, it's almost totally unheard of for an individual to buy a week's worth of any type of food (even rice). How much less likely are they to buy a non-essential tool like a flashlight? No wonder the creators speak of "villages" buying these... But that assumes these cultures have villages with their own purchasing power - do the villages collect taxes and have officials which then spend the public money pool? Maybe it will help the developing countries, but it seems a little naive.

Nevertheless, it's a good PR angle for them to get more funding. Practically, I'd love to see those things sold on Amazon or something for ~$20. They look like really good units for off-the-grid homes.

LIghts like these are critical to getting countries back up on their feet. Schools a few and far between. Education is hard to come by. Many of the kids will travel large distances every day to school and back. When they get home, they can't do any homework because they have no light. These kids want to learn, but they lack the tools to do so. Being able to do homework, or even just read books can make a huge difference.

I don't think this is naive, it's a genuinely good idea that could really make a difference. I wish them the best of luck.

Know who they should talk to about funding? Bill Gates. He's all into that shit these days.

It's publicly funded and they are about halfway to their goal. Drop them a couple bucks: http://www.indiegogo.com/projects/282006

Bio: We are Martin Riddiford and Jim Reeves, London based designers who have spent 4 years developing GravityLight as an off-line project. We work for therefore.com, which has over 20 years of experience in designing and developing hand held computing and communication products for a host of pioneers including Psion, Toshiba, NEC, TomTom, Inmarsat, ICO, Sepura, Racal Acoustics, Voller Energy, FreePlay and SolarAid.

We’re using a tried and tested manufacturer who has the right expertise to make GravityLight. We have some links to partner organisations in Africa and need to do the same for India. If you're part of an organisation and would like to get involved then please contact us.

Imagine a village that takes 7 hrs by dirt road, a boat ride and a walk of 2 hours to reach. Lamps and fires are sustainable because people can understand, maintain, and fix them.

The answer to poverty is not fancy engineering and technology. It's understanding the context of the problem.

Potential energy and LED's are a great idea... but why do people have to spend a weeks worth of food on your plastic device?

Go back and redesign this with every day items, a rope, a pulley, cogs maybe something as a fly wheel. Make it open source.

Smarter Every Day: Turning Gravity into Light has been added as a related post - related requested by eric3579 on that post.