When her 21-year-old daughter died in a sledding accident in early 2007, Pam Weiss had never logged onto Facebook. Back then, it was used almost exclusively by the young, like her daughter Amy, a student at UCLA. But Weiss knew her daughter had an account, so in her grief she turned to the social-networking site to look for photos. She found what she was looking for, and more — she was soon communicating with her daughter’s many friends, sharing memories and even piecing together a blueprint of things Amy had hoped to do in the future through posts she’d written. “It makes me feel good that Amy had a positive effect on so many people, and I wouldn’t have had a clue if it hadn’t been for Facebook,” says Weiss.