I was reading some of the discussion here 
http://www.tfproject.org/tfp/showthread.php?t=101073 
and had some thoughts that probably deserve their own thread.  That said, what constitutes a religion?  
Personally, I'm about as non-religious as they come.  I can't really classify myself as an atheist or an agnostic because at the end of the day, I just don't care.  God (or the lack there of) has never played a serious role in my life despite the fact that I went to church every Sunday until I was about 16, and I only stopped because my travel schedule for some activities that I was involved in conflicted.  I had some great friends at church, but God was never a part of the equation.
Now that I've fully disclosed my starting point, I'm wondering what constitutes a religion.  Obviously most of the world falls into the 5 major ones - Christianity, Islam, Buddhism, Animism, and Hinduism.  There are variations on the theme, but I think that I've hit most of them.  
In the other thread, someone made the comment that the use of healing crystals could be a religion, and that started my brain going.  Once you're outside the bounds of the major religions, how do you determine what's a religion and what doesn't?  Back in the day, I used to tell people that my church was the long runs that I did on Sundays, and I honestly felt that I was communing with something although that was admittedly the endorphins coursing through my bloodstream since I only felt that way when I was running.  Does believing in the healing power of crystals constitute a separate religion, even if it is compatible with another faith?  I think that Scientology claims that they are not a replacement of another faith but more of a compliment, which only serves to confuse the likes of me.  
Thoughts?