CARAT JUICE: While she arrived bright and early at the Cartier mansion on Thursday morning to help launch a new Cartier Trinity Charity bracelet to benefit the charity ServiceNation, Demi Moore made it clear the bracelet isn’t her favorite piece from Cartier — as she flashed a megawatt emerald-cut diamond ring given to her by husband Ashton Kutcher. “It’s vintage Cartier,” the actress said coyly. Moore is an advocate for ServiceNation, a coalition of 190 nonprofit organizations that seek to expand opportunities for Americans to volunteer for national service. The limited edition Trinity charity bracelet is made of yellow, white and rose gold with diamonds, comes on either a red, white or blue silk cord and goes on sale for $1,700, with $350 going to ServiceNation. “Cartier has been supported by America for 100 years,” said Frédéric de Narp, president and chief executive of Cartier North America, who was joined by Bernard Fornas, president and ceo of Cartier International. “We want to entice Americans to give back.”

This story first appeared in the May 1, 2009 issue of WWD. Subscribe Today.

HOW TWEET IT IS: In the tradition of press conferences everywhere, Rachel Roy’s Thursday afternoon started late — by about 20 minutes. However, Roy’s was a bit different: It took place on Twitter instead of in a boardroom. The designer, who admitted at Wednesday night’s launch party for her Macy’s line that her staff had to give her a 10-minute tutorial in the microblogging service, answered queries fans had posted online. While the questions weren’t the most hard-hitting (“Rachel, you absolutely glow! How do you stay confident through tough times?”), she did touch on everything from social media to her inspirations (graffiti, travel, the smell of libraries and “my gay husbands”). She also hinted at expansion: When an acolyte asked, “Are you going to extend your fabulous frocks to us Curvy Fashionistas size 14+?” she replied, “I would love to do a plus-size line.”

has cast another surprising personality for his next Chanel handbag campaign: Lily Allen. “She’s fun,” enthused Lagerfeld, who plans to turn his lens on the British pop star next week.