U. S. Religious Knowledge Survey conducted by the Pew Research Center's Forum on Religion and Public Life. Most discussions seem to focus on the finding that atheists and agnostics as a group scored higher on the survey than did persons with affiliations to conventional religious groups. The Executive Summary discusses this result and the other observations from the survey.
The Pew site also offers a abbreviated quiz for the general public (15 questions, compared to 32 on the actual survey). My results are shown above; I missed just one question (on the Jewish Sabbath - forgive me, Ira!). I should think that most TYWKIWDBI readers will do just as well, because the questions do not really require knowledge of dogma or doctrine - just simple knowledge about Mother Theresa and Bible stories and Ramadan and such. What surprises me is how poorly the public does on what seem to be basic knowledge questions. Below are the results (sorted by religious affiliation) for the abbreviated quiz, which I invite you to try at this link.