I received this link in an email. I found it interesting.
They discuss pica disorders. Here is a link to the explanation of those: http://emedicine.medscape.com/article/914765-overview
The show, "My Strange Addiction" has covered a number of these. You can go to the TLC website for this show here: http://tlc.discovery.com/tv/my-strange-addiction/
I hope this is useful!