Money which can found to help Africa would be better spent on working towards fixing the underlying problem, than on saturating the continent with DDT (which is not completely harmless to human health). A major DDT program there now, would only result in slightly larger, but still hopelessly backward and sickly population. Most Africans who would have died of malaria will just die of some other preventable disease a few years later.
I think there's a big danger in making large, fast-growing, backward populations increasingly dependent on handouts from developed countries, of technologies that the recipients can't begin to understand. They need to be taking control of their own lives and communities, and our efforts should be directed towards progress in that area. Teaching them to use nets, and teaching them to teach each other to use nets would be a good start. Today's front page NYT article is a good illustration of how urgently very basic things need to be attended to. Many girls in sub-Saharan Africa don't go to school past puberty, even if they and their parents want to, because there are no latrines, much less sanitary pads. Many of these girls will be married off and pregnant before they're fully grown, and many will die in childbirth.
http://www.nytimes.com/2005/12/23/international/africa/23ethiopia.html?hp&ex=1135400400&en=2e719b5791aa1cec&ei=5094&partner=homepage