A string of pearls may scream Barbara Bush, but the deb fave is on an upswing. ”We’re looking at 2002-03 as our next peak,” says Devin Macnow of NYC’s Cultured Pearl Information Center. Pearls swung on the runways of Alexander McQueen, Anand Jon, and Ralph Lauren, and circled the necks of Pink, Kristin Scott Thomas in Life as a House, and Julia Roberts in Ocean’s Eleven. Sarah Jessica Parker sported multiple strands on Sex and the City, while NYC’s American Museum of Natural History has a popular exhibit devoted to the June birthstone. ”In rocky economic times, people tend to reach for the classics,” says Harry Winston’s Jim Haag. Pearls of wisdom?