Update. Excellent site.
No one really knows why these were made or for what they were used. An article here and here gives some ideas and background. There is a facebook page where you can throw out your own ideas. There is more information out there, so just google it.
I will dismiss its religious use off the bat. I will meander about the next day or two and see if I can locate some well researched articles concerning the artifact so that there is some context for it - and presumably better interpretations for its utility will follow.