www.ted.com Negative images of Africa dominate the news: famine and disease, conflict and corruption. But Ngozi Okonjo-Iweala, the former Finance Minister of Nigeria and now a director of the World Bank, says there's a less-told story unfolding in many African nations: one of reform, economic growth and business opportunity. Cracking down on corruption -- and the perception of corruption -- will be the key to its success. She tells how high-ranking Nigerian officials taking money illicitly have been jailed, and how citizens and prospective business partners are getting at least a partial picture now of where money flows.