World War II had its “V-mail” – photographed, miniaturized letters both to and from servicemen. Today’s war has e-mail. “In Iraq, there were guys who’d been in for more than 20 years who would constantly give us young guys crap,” about using technology to communicate, says Marcus Penn, a 25-year-old Marine from Beaufort, S.C. “They’d say, ‘When I was in Desert Storm, ...