There's this neat little test on Beliefnet.com that purports to tell you which religion your spiritual beliefs fit most closely. My top 3? Neo-Pagan, Mahayana Buddhism, and Unitarian Universalism. Which is bad considering that I usually think of myself as a Christian.
Worse than that: out of 26 religions, Catholicism came in at 25th for me. The only one below that? Jehovah's Witness.
Also, please note their disclaimer: Warning: Belief-O-Matic™ assumes no legal liability for the ultimate fate of your soul.