SLAVES to the rich and famous, unite. Not only do celeb assistants have a 120-person exclusive organization called the ACPA (Association of Celebrity Personal Assistants), they also have an annual get-together at which they can commiserate. The press release for ACPA’s event Tuesday at the Hotel Bel-Air describes the crew as a “tight-lipped crowd who are not only discreet but also organized, as in a professional society.” We’d like to eavesdrop after the members knock back a few cocktails.