Smart Dust is back in the news today with a press release from the University of California. Researchers there claim that Smart Dust can be used in the war against terror by rapidly detecting chemical or biological agents dumped into water supplies or the atmosphere. From the sound of it, though, what they're working on are photonic crystals that don't actually have any intelligence. We've done several articles on nano-scale robotic Smart Dust in the past (including how to buy your own and their potential role as pollutants).