It turns out that 17-year-olds probably aren't that good at studying electrical interference -- and its effect on pacemakers -- created by iPods. Unlike the data presented to the Heart Rhythm Society last year by a high-school student, which demonstrated the music player's ability to interfere with heart-regulating devices, the FDA now says that the gadgets are completely safe for use. Researchers measured magnetic fields produced by four different models of Apple's ubiquitous device, and found no reason why your grandmother can't keep jamming to her South of Heaven reissue. Said FDA researcher Howard Bassen, "Based on the observations of our in-vitro study we conclude that no in