Technology, traditionally seen as the enemy of the environment, is likely to be a positive environmental force in the 21st century, and not only through its application to feed the 8-12 billion people that will occupy the planet. Technology is also likely to be central to improving overall quality of life. Nevertheless, 21st century technology will have to consider the potential environmental impacts of its every action. The process of so doing, termed industrial ecology, is rapidly entering planning, product design, and customer response activities throughout the world. Industrial ecolgoy works in cooperation with environmental science, and incorporates new environmental knowledge in its decision-making processes. The tools of industrial ecology, including life-cycle assessment, design for environment, and materials flow analysis reveal that the potential benefits to both corporations and the environment of optimizing technology-environment interactions are substantial. Some examples of such optimization will be presented and discussed.