The marketing campaign for 21 Grams – a series of posters asking variations on the question, ‘How much does life weigh?’ – is more artful than the movie, because the film itself is anindulgent exercise that could use some of the streamlining a poster demands. With flair and pretension, director Alejandro Gonzalez Inarritu follows three tortured souls (Naomi Watts, Sean Penn, Benicio Del Toro) connected by an accident. The movie weighs a good 10 pounds too much.