In the developing world, the answer to the persistent problem of sanitation and open defecation is not in building more toilets, but in treating the fecal sludge that fills up the built toilets, and reders them useless due to low maintenance availability. In developing countries, the treatment followed in developed countries is not carried out, and so a new way is needed. For example, Waste Enterprisers, have been helping transform fecal sludge into industrial fuel, much like coal. Their next step is to make biodiesel out of it. Read more here.