This document discusses opportunities for libraries to engage with users through social media and collaborative curation. It defines social media and produsage, and outlines key principles of open participation and communal evaluation in these environments. The document proposes that libraries can use outreach via social media to build loyal communities, encourage users to create content, and harness user expertise through co-curation to identify interests and curate user-generated content. By engaging with produsage communities and their leaders, libraries can help users develop professional skills and careers in collaborative curation.