So far I've made a Rorschach mask out of some old t-shirts, and it looks pretty good to me. The ink doesn't move, of course.
I also have a comic version of the smiley face pin, a framed team photo of the 1940's Minute Men and Nixon's Presidential Order allowing Dr. Manhattan to fight in Vietnam (soon I'll paperclip the photo of the VC bowing to Dr. M to it).
Eventually, I hope to get Rorschach's improvised flamethrower (aerosol can and lighter), a can of beans, Rorschach's symbol note thing, a replica issue of the Black Freighter and Hollis Mason's Under the Hood hardcover.
I will very likely want more props after the movie comes out, depending on whether it's as awesome as I hope.