Presentation delivered at both the 2008 Nebraska Library Association Paraprofessional Section Spring Meeting and at the 2008 NLA/NEMA Fall Conference. Abstract: Every library has invisible barriers that dampen cooperation, from the division between public services and technical services to the division between paraprofessionals and librarians. Communication and cross-training are the keys to bridging those divides. Communication takes many forms, and multiple approaches reinforce each other. Casual communication includes conversation with people from other departments, such as hallway chats and informal meetings. Formal, library-wide communication includes the use of e-mail aliases, discussion lists, blogs, wikis, meetings, staff forums, and newsletters. Cross-training comes in three flavors: positional clarification (telling), positional modeling (showing), and positional rotation (doing). Any of these styles can enhance understanding of one another's jobs. Even library-shaking events such as strategic planning and departmental reorganizations can be used as opportunities to build alliances between departments. A library where employees regularly talk and interact across departmental lines is much stronger than a mere collection of departments.