[behindthemask]

I would agree with Jason Abbadon go crazy. Get some city or space backdrop for a sick look, you could even go on say deviantart.com and search for ruins or destroyed city some godzilla type backdrop and some printers will format the image to fit a large scale and simply print it out and tape it to the wall or get it made. You can buy tons of custom wallpaper as well such as rock,brick, etc.. other then that go: Buy Posters, Framed Prints and Art Posters at AllPosters.ca

just about any poster you could want, if you want super vintage/throwback check out ebay. or check for comics with the 2page posters or fold out ones.