WHEN THE YOUNG MEET THE LESS young, sometimes tact is tested. At the second annual fund-raiser carnival for the Pediatric AIDS Foundation, held at the old Robert Taylor estate in Los Angeles, Nancy Reagan met the New Kids on the Block and vaulted generations with grace: "Oh, yes, yes," she chirped, "I've seen you on television." Later, a little fan greeted Robin Williams with off-the-Mork cries of "Na-nu! Na-nu!" Robin gently snapped the lad into the '90s, remarking, "No, no. Used to be."

Hey, when the cause is good, anything is tolerable. In all, 1,200 Big Ones of screen and sports, including Tom Hanks, Ellen Barkin and Danny Sullivan, contributed $1,000 each to the group cofounded by anti-AIDS crusader Elizabeth Glaser and took their turn as carnies June 9. Alan Alda managed a Wheel of Fortune booth, Mel Harris supervised a ring toss, and John Candy watched for cheaters at a ball roll. When one of Jeff Bridges's daughters inquired as to the identity of a certain hipster ambling nearby, Dad obliged with a history lesson. "That's Little Richard," Bridges said. "He's one of the people who started rock and roll."