This document summarizes the NMC Horizon Report: 2012 K-12 Edition, which examines emerging technologies that are likely to enter mainstream use in K-12 education within the next 1, 2, or 3-5 years. Technologies on the near-term horizon (1 year or less) include mobile devices & apps and tablet computing. Game-based learning and personal learning environments are on the mid-term horizon (2-3 years). Augmented reality and natural user interfaces are on the far-term horizon (4-5 years). The report was created by an international advisory board to identify significant trends, challenges, and technologies in pre-college education.