Three leaders of mid-market companies share their best practices for reinventing their companies in this uncertain economic climate, demonstrating that a great deal can be accomplished despite constraints on capital and spending. Quill Corporation, a Midwestern subsidiary of office supply giant Staples, used a TV “reality show” approach to identify the “next big niche.” Nektar Therapeutics, a drug-delivery services provider for larger pharmaceutical concerns, is recasting itself as a developer of therapeutic drugs. Cascade, a supplier of injection-molded plastic parts, is capitalizing on the “clean tech” wave to inspire new business.