Americans feel there is more greed on Wall Street now than in the recent past, a poll by the Gallup Organization shows. The poll, published in Newsweek magazine, says 80% of those surveyed felt people in big business and on Wall Street seem "more greedy" now than five years ago. The poll shows that 5% think American business is less greedy and 8% think it is the same. Asked if they were involved in any charity or social service activity--such as helping the poor, the sick or elderly--49% said "yes" and 51% said "no." Those figures compared with 29% in the "yes" column five years ago and 71% in the "no" column, the magazine said. Gallup interviewed a national sample of 606 adults by telephone Dec. 16-17.