I just finished reading Muhammad Yunus' amazing book Banker To The Poor. It describes his efforts to set up a microcredit bank called Grameen, and it's a heck of a story. It almost makes me want to become a banker.
He started in 1976 with a $27 loan to a few of the poorest people in Bangladesh. A few decades later he's lent billions and helped millions of people lift themselves out of poverty.
One of the things I love about his story and his approach is the emphasis on speed & simplicity. He is totally focused on delivering credit to the poor and has no time for the complexities, formalities and delays inherent in traditional banking structures. The results (including a Nobel Prize) speak for themselves.