I have long been an admirer of the work of William McDonough. In February of 2005 he spoke before TED, and his talk was posted in April of this year (2007). I recommend the 20 minutes that it takes to listen to it.
TED’s introduction to McDonough runs like this: “Architect and designer William McDonough asks what our buildings and products would look like if designers took into account “All children, all species, for all time.” A tireless proponent of absolute sustainability (with a deadpan sense of humor), he explains his philosophy of “cradle to cradle” design, which bridge the needs of ecology and economics. He also shares some of his most inspiring work, including the world’s largest green roof (at the Ford plant in Dearborn, Michigan), and the entire sustainable cities he’s designing in China.”