 Knowledge saves a life when a mother recognizes that her child is suffering from extreme dehydration, but she knows she can use oral rehydration salts. Knowledge saves a life when a subsistence farmer sees how he can double his crop yield by using newly learned agriculture techniques. But to get this kind of knowledge to the very poorest people on earth, you can't rely on what works for the rest of the world. Let's take an example how TED spreads ideas. TED Talks are available online. There are transcripts and captions in 100 languages nearly. And you can even watch a TED Talk on your smartphone. Now, this reaches millions of people, but it doesn't reach the poorest billion people. And that's what I'm interested in. If you live on $1 a day, you can't afford a smartphone. If you can't read, text isn't useful to you. And if you live without electricity, it's very difficult to get online. So this is the problem that I've been working on for the last five years, is how can you make on-demand knowledge available to the very poorest people, people who are illiterate and live in the most remote rural villages? So I started a nonprofit called Literacy Bridge to work on this. And I spent some time in the very poorest region of Ghana. And while I was there, I learned how agriculture specialists will travel to remote rural communities and they will share their knowledge on how to produce organic fertilizer or the proper spacing between seeds for a particular crop. I saw that nurses would do the same thing and they would teach women about particular breastfeeding techniques or what the right proportion of sugar, salt, and water is to save a child from dying of dehydration. And just amazed by all of this local knowledge that was there, but there is a problem. And that is that after a little while, people would tend to forget this information as we all would. Because if you're illiterate, you can't take notes. So my attempt at solving this problem was to develop a device that would allow you to provide on-demand knowledge to people in the poorest areas. What we did was to create a low-cost, durable audio computer. And through a lot of user testing, we ended up with this device that serves as like a household library of information. It's recorded by local experts who speak the local language. You can run multiple-choice quizzes on it. You can follow audio hyperlinks. It tracks everything that you are listening to so that it knows what are people most concerned with so you can improve the content. If you have access to a smartphone, you can copy downloaded content from that, but you can also copy content from any other device. Now, the solution to a problem like this is never about technology alone. It's always got to be much more than that. So what we've learned is that you need to survey these communities to understand what needs do they have. What do they already know, and what resources do they have? Work with local experts to understand what knowledge and to match that with the needs, and to use really creative ways to engage people. To make sure you keep that content going and keep it updated, because everyone wants refreshed new things, and to listen to feedback. But there's something else. You need a sustainable business model. You need to be able to figure out how are you going to keep this replicated. So the approach we're using is we provide these devices into the villages for free, and then we offer a service to government agencies, to nonprofits, and businesses that are trying to get this information out to people. And if we do this right, we hope to replicate this. Just imagine one billion people who, if they had knowledge, what could they do to change their lives and to save other lives?