2 interesting articles: http://www.sciam.com/article.cfm?chanID=sa006&colID=13&articleID=5B90A7E1-E7F2-99DF-3083871CC967A052 http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=5BBE6143-E7F2-99DF-333BD2110A8790EE Craig