What can be causing the constant 'clicking' of my lumbar every time I move?

It's not that 'pop' or 'crunch' sound like cracking your knuckles or going to the Chiropractor for an adjustment, it's more of a constant 'clicking'. So here are a few ideas about that, I guess I can almost take my pick of reasons listed...

http://www.buzzle.com/articles/clicking-in-lower-back.html

Well after reading the article I think I would have it checked out some thing could be out of line.