MisterPoll has a collection of dozens of religious polls
submitted by individuals. The results are not necessarily accurate
because the total number of contributors is low and they are
self-selected. Some of the polling questions are delightfully biased.
See: http://www.misterpoll.com/
The Gallup Organization is probably North America's best
known polling agency. Unfortunately, only limited polling data is
available without a subscription. See:
http://www.galluppoll.com/
The Pew Forum on Religion & Public Life "... gathers
and disseminates objective information through polls and reports. ... It
provides a neutral venue through its various issue roundtables and
briefings for discussions of important issues where religion and
domestic and international politics intersect." See:
http://pewforum.org/
Roper Center for Public Opinion and Research has collected
the results of thousands on polls on questions related to: