GREETINGS, a putative comedy, is a very early effort from director Brian De Palma and star Robert De Niro, neither of whom has ever been noted for his comedic talents--and for good reason. This nearly plotless--and distinctly '60s--film is too meandering and self-satisfied to add up to much, but it's good for a few mild chuckles.Bobby De Niro and his knockabout pals screw around New York for an hour and a half, thumbing their noses at the establishment, avoiding conventional employment, and basically being irresponsible. Bobby's trying to escape the draft; meanwhile, his friends experiment with computer dating and attempt to solve the JFK assassination (which occasions a few decent BLOW UP gags). The film is really a bunch of comedic riffs strung together; it goes nowhere in particular (though, for the record, Bobby does end up in Vietnam after all) and it has a droning quality. Scenes tend to drag on too long. And its satire, though here and there effective, is generally unsubtle and off-puttingly smug, as if De Palma thought that mocking right-wingers were in and of itself a grand achievement.Even in 1968 De Palma was into voyeurism: one lengthy scene shows De Niro as a peeping tom. Serious film students might find more of De Palma's style here in utero; others would probably be better off looking elsewhere for their kicks.