Cinmaffiche http://www.cinemaffiche.com/index_e.html
Original movie posters for collectors. Most of them are French, of all sizes, and some are on linen, from muted cinema to nowadays. Site available in English or French.
Posterman http://www.postermandan.com/
An online dealer of vintage film posters indexed by title, director, and featured actors. Dealer accepts payment via credit cards, checks, and paypal.
Spanish Film Posters http://www.spanishfilmposters.com
An Online merchant specializing in Spanish versions of posters for popular American movies. Availability of inventory is done via email and payment is made via paypal.