Look for the next generation of computer viruses to target mobile devices, from smart phones to PDAs. In June, hackers distributed a virus dubbed Cabir to a handful of security firms to prove that concept. The virus targeted devices running on the Symbian operating system with Bluetooth technology activated, including high-end Nokia, Motorola, and Sony Ericsson phones, as well as BlackBerries and some laptops. The bad news: Infected devices can broadcast the virus over a 30-foot radius to users with like machines that also have Bluetooth switched on and set to accept files from unknown "partners." The good news: Only an estimated 10 million mobile phones are Bluetooth-activated worldwide. The long-term worry: A spate of viruses could force carriers to beef up their customer support staffs, which would drive up prices for all users.