Demi Moore brought some star power to Cartier's Fifth Avenue mansion Thursday morning when she arrived to support a partnership between the famed French jewelry and Service Nation. "Cartier has chosen a fine gem in Service Nation," declared the actress, who spoke following brief words from Cartier International president Bernard Fornas and North American CEO Frédéric de Narp. "It's about creating a new culture of service in America." All the hoopla was in honor of Cartier's centennial celebration this evening, during which a special coffee table book entitled Cartier I Love You shot by Bruce Weber will be unveiled. Sporting her vintage Cartier diamond engagement ring on her left hand, Moore also sported a special Trinity bracelet designed to benefit Service Nation. The new limited-edition bracelet in 18-karat yellow, rose and white gold and diamonds is available on individual red, white and blue silk cords at Cartier boutiques nationwide ($350 of the $1,700 retail cost of each bracelet will benefit Service Nation). "It's an extraordinary time for a service movement," de Narp declared. Moore could not have agreed more, professing that she fully expects the "Twitter Nation" she and her husband Ashton Kutcher have adopted to put their full force behind the initiative.