http://www.kqed.org/.stream/anon/radio/quest/2009/03/2009-03-09-quest.mp3
A group of high school students in San Francisco are using high-tech GPS cell phones to track their daily carbon footprint - and to gauge their daily environmental risk. The GPS tracks the students' trips and shows them how much carbon they use and are exposed to each week. As cell phones become more powerful, organizers hope to spread this movement virally.