Attendees say the memorable moment from this year’s amfAR Life Ball benefit in Vienna was watching Diane von Furstenberg, Kenneth Cole, the Misshapes, Whoopi Goldberg, Rebecca Romijn and Jerry O’Connell run for cover under pink rain slickers Saturday night, when a thunderstorm drenched the crowd of 25,000. Most of the VIPs — flown from New York on a private plane organized by promoter Josh Wood — later went to the ball for 3,000 inside Vienna’s City Hall, where they danced in sopping wet tuxedos and gowns till 4 a.m.