In the kingdom of cyberspace, youth still rules, of course. But there is an invasion under way, led by the likes of Sara Trabish. This unlikely foot soldier is an 82-year-old great-grandmother who keeps her family connected with e-mail. A grandson in Maryland sends her dirty jokes. Her great-grandniece and great-grandnephew, both 13, love being on her online network and have gotten to know her better. "I feel good about building ties with a younger generation," Trabish says.
Experts differ on numbers, but most agree that people 50 and older make up the fastest-growing group online. Some, like Trabish, want to...