ARDA: Association of Religtion Data Archives
"The ARDA Data Archive is a collection of surveys, polls, and other data submitted by researchers and made available online by the ARDA. There are over 1,000 data files included in the ARDA collection. You can browse files by category, alphabetically, view the newest additions, most popular files, or search for a file. Once you select a file you can preview the results, read about how the data were collected, review the survey questions asked, save selected survey questions to your own file, and/or download the data file."