Maggie Gyllenhaal sent a note explaining she was “in pajamas” Monday rather than at the premiere of her sexy new film, “Hysteria.” But she had a good excuse: the birth of her second child just weeks ago. At a Hotel Chantelle bash, star Hugh Dancy circulated with Patrick Wilson and Mamie Gummer. But gifts by saucy sponsor Jimmyjane caused a bigger stir. “They gave vibrators to every guest,” a spy said, “including Angela Lansbury, who claimed it was her first.”