svsg, I'm not tech-savvy for this kind of stuff, but I think Zodiac accomplished two things, visually: overall and throughout, it looked like a Fincher film. Smooth, slick pans and tracks, eliminating the limitations of space (by crabbing through walls, etc.) - note the birdseye-view shot of the taxi, which was very neat, I dunno how he did it. Secondly, depending on which decade it was, I thought, as well as looking like Fincher (in visual style), it evoked that decade (in terms of visual feel). The sixties, seventies and eighties portions all looked very subtly different. It wasn't as obvious as Scorsese's same technique in The Aviator, though, probably because changes in look weren't as obvious in the 60s-80s as in the 30s-50s.

Not only did Zodiac have period detail in terms of mise-en-scene (props, locations, fashions and clothing, etc.) but the way in which it was filmed, too. It's a very self-reflexive film.