craftgrrl | HAUNTED HOUSE CO-ORDINATOR!

First off - Happy Fall Everyone! The Halloween season is upon us!
I'm wondering if any of you wonderful crafty people can help me out with a Halloween-related crafting conundrum.
I am SO FREAKIN EXCITED because this year, I am the Haunted House Co-Ordinator for York University's Halloween Bash! :D So awesome. Anyway, I have a question for anyone who has done haunted houses or any sort of heavy duty decorating - what are some things that can be used as inexpensive wall covering, or even wall-buiding material? I'd like to veer away from the traditional black-garbage-bag solution, because while nice and cheap, it just looks too... well, cheap. I'd like to keep it cheap as much as possible, but I find the shinyness of the bags too distracting and a constant reminder that you are in a man-made haunted house... I dunno, I find it prevents you from really getting into it? Maybe that's just me, but I wanted to look into other options like maybe a really inexpensive black fabric or maybe sheets of black plastic? Possibly some-other-material + black spraypaint? What have others done?