This chapter proposes a category of tools called design objects that can be used by instructors to integrate existing content sources, including but not limited to learning objects, within teaching frameworks that engage learners with content in meaningful ways. Emphasis is on tools to support the K-12 instructor, although related issues are applicable across educational levels. Examples of teaching-oriented design objects are provided along with related development systems, however it is argued the former represent more viable options for teachers given limitations in the learning object economy, conceptualizations of teachers regarding objects, complexity in packaging objects, and classroom control issues. The possibility of design objects and development systems working in tandem is discussed, with development systems prescribing effective educational strategies for novice teachers and design objects supporting more personalized content development. Various sources for new design objects are suggested to encourage further development and research.