New trends are taking hold among the well-to-do, Robert Frank reports. Conspicuous benevolence has become passe, leading to a phenomenal surge in anonymous philanthropy, he writes. And some wealthy folk, like Floridians Richard and Amanda Peacock, are resorting to "selling off all their homes and all their possessions in a single day," he says. "I got a wildebeest for $250!" one bargain-hunter crowed over a pre-owned safari trophy.