Feel that Buster Keaton film is just too silent? Want a little real-life combative action to go with your Iraq documentary? Then hobble over to the Museum of Modern Art, where the classic films shown at the Roy and Niuta Titus Theaters and the Celeste Bartos Theater attract crotchety old people who feistily compete with the screenings. These goofy geezers act up, talk back, yell at each other, and generally turn the experience into a geriatric version of The Rocky Horror Picture Show. But you?ll forgive them because they?re so entertaining, and besides, they?re probably in that Buster Keaton movie.