Singer's book talks about finding and supporting effective charities. Here's one I now support that seems pretty direct: https://www.fistulafoundation.org
It also made me rethink what I am doing with my life/career. Is creating apps for well-off people with iPads the best use of my time? Is getting rich and donating most of your wealth a good strategy? What's the biggest problem I can personally solve?
I'm still trying to figure it out.