Wired has a
write up of how some UC Berkeley professors and graduate students want to save the world by equipping cell phones with
radiation sensors and turning them into inexpensive distributed platforms.
They are working to develop cheap wireless sensors that, once fitted inside cell phones, could sniff out anything from biological weapons to traffic patterns. While the sensors might not be a typical cell-phone add-on, those involved in the research claim the sheer number of mobile phones in use could make such a system a boon for worldwide data collection and problem solving.
What a novel and worthwhile idea!