Social media such as Facebook, Twitter, blogs, wikis, Flickr, and YouTube have garnered a billion users and their popularity is spreading rapidly, particularly on mobile devices. Technology-mediated social participation (TMSP) is a useful term for describing how these social media tools, user-generated content sites, discussion groups, problem reporting, and volunteer systems can be applied to national priorities. Provocative examples suggest transformative applications for healthcare/wellness, disaster response, energy sustainability, cost-effective education, and economic health. Additional new missions for these sociotechnical infrastructures include cultural heritage, political participation, environment/climate protection, public safety, international development, and local civic involvement.