The Independant Entertainment News (iesb.net) hosts 9 clips from the film, that are guaranteed to make every FincherFanatic drool! Far more than the theatrical trailers these give you a hint of the timing, the feel and tempo of the film.
For everyone who has not already been all over the Zodiac case and dug into it's personas and chronology: There may be spoilers!
Since there is no earthly way around watching the clips at least a dozen times, why not go update yourself about the case (over at zodiackiller.com, a website on the case and primary suspects).
Then head over to IESB to fire yourself up for one heck of a cinematic release!
This way to the clips: