I used to get pretty incolved with props, from hand-inked maps (i.e., inked with a quill pen in iron gall ink) on faux parchment to museum reproductions of roman currency (the museum gift shop had a run on them). I haven't done that for years now -- I often found that campaigns fell apart due to time/scehdule constraints before they get played all the way through and, in the end, there was a lot of wasted effort on my part.
Today I still do PDF handouts for the group (when I have one) and update a dedicated website, but I stay away from props (unless I'm printing out a letter from an NPC or something). I do have some 2500 fonts installed on my PC for the PDf stuff, so if I have to make it look convincing, I can (one pass with funky fonts, another with Photoshop textures and I'm set).
One thing I want to do for the next game that I run is send out a weekly in-setting news rag. I've begun to incorporate moveable type into some of the settings that I design so I'll have a reason to do this -- Balphor (in vs. Elves) has printing presses, for example.