Message boards at The Exorcist Online
Since IMDB is closing its message boards, Exorcist fans are more than welcome to register over at TheExorcistOnline.com, a new website run by some of the old members from CaptainHowdy.com and BehindTheExorcist.com (CH.com was sold off almost 2 years ago, and has been pretty much abandoned since).
http://community.theexorcistonline.com/