A new report released today by the nongovernmental Worldwatch Institute urges better monitoring of trade in natural resources taken from conflict zones, saying that such imports fuel brutal conflicts in the developing world..."Brutal wars over natural resources like coltan -- a mineral that keeps cell phones and other electronic equipment functioning -- diamonds, tropical woods and other rare materials have killed or displaced more than 20 million people and are raising at least $12 billion a year for rebels, warlords, repressive government and other predatory groups around the world," the institute says...Opium, gems, oil, timber, natural gas, precious metals, coffee and cocoa are among the resources cited as helping to pay for wars over the past 50 years.