I donate to Wikipedia and the archive.org. I practice rational ignorance: I estimate that the costs of learning more about effective charity are far above the costs of doing it wrong. Maybe Wikipedia uses the money to create more and more small-fry side-projects (Wiki-maps, wiki-this, wiki-that). Maybe it funds Wikifeet, which is thoroughly weird. I don't care -- Wikipedia is one of the greatest accomplishments of H. sapiens sapiens.
(Malaria is still a big problem, and it's so cheaply improved upon -- if that touches your heart, go for it!)