iTunes also has a "Film Montage" for free that runs just under two minutes. You can purchase the Watchmen Motion Comics. So far six chapters are available for $1.99 each or you can get the "season pass" for $19.99 (the same price as the graphic novel but with voice acting, music, etc). Just go to iTunes and type Watchmen in the search. There's also an "Essential Watchmen App" coming soon.
March is getting closer...
EDIT: HERE's the link if you don't want to try searching it.