This book offers a summary of different lines of thought on how Information and Communication Technologies (ICTs) can be used for promoting the ideal of peace, for example by helping to manage a crisis, by supporting development and education, by overcoming authoritaran regimes, or by promoting a global civil society and global culture of peace. After introducing these ideas, the concept of a "Peace Box" is presented, which is a small computer-like device that can be set up in any home or office to provide applications and services for actively supporting the various visions of using ICTs for peace.