This document discusses the history and growth of social media and its increasing use by government agencies. It notes that one-third of US internet users now use social media and new tools to access government services and information. For those users, government is becoming more participatory as nearly one-quarter publish commentary online about government issues. The document also outlines how government agencies at different levels have begun using social media platforms like Twitter, Facebook, and YouTube to communicate about issues like the Gulf oil spill, storm reporting, and public health initiatives. It introduces the concept of "Government 2.0" or using new technologies to enable more efficient delivery of e-services and practices like open government.