New ideas are the precious currency of the new economy, but generating them doesn't have to be a mysterious process. The image of the lone genius inventing from scratch is a romantic fiction. Businesses that constantly innovate have systematized the production and testing of new ideas, and the system can be replicated by practically any organization. The best innovators use old ideas as the raw materials for new ideas, a strategy the authors call knowledge brokering. The system for sustaining innovation is the knowledge brokering cycle, and the authors discuss its four parts. The first is capturing good ideas from a wide variety of sources. The second is keeping those ideas alive by playing with them, discussing them, and using them. Imagining new uses for old ideas is the third part--some knowledge brokers encourage cross-pollination by creating physical layouts that allow, or even force, people to interact with one another. The fourth is turning promising concepts into real services, products, processes, or business models. Companies can use all or part of the cycle. Large companies in particular desperately need to move ideas from one place to another. Some will want to build full-fledged consulting groups dedicated to internal knowledge brokering. Others can hire people who have faced problems similar to the companies' current problems. The most important lesson is that business leaders must change how they think about innovation, and they must change how their company cultures reflect that thinking.