Much has been said in the news about finding alternative sources for fuel energy. This article from Discovery News, however, highlights another alternative source, for rubber, which is apparently another resource that is hard to come by. Scientists from The Ohio State University’s Agricultural Research and Development Center in conjunction with the
"No matter how much chemistry we've applied, we still haven't been able to find an artificial substitute for natural rubber. We're still harvesting [rubber] the same way they did 1,000 years ago; by cutting into the tree and letting the sap drip into containers. It's not a very efficient system."