This book constitutes the refereed proceedings of the International Conference on Embedded and Ubiquitous Computing, EUC 2006, held in Seoul, Korea in August 2006. The 113 revised full papers presented together with 3 keynote articles were carefully reviewed and selected from over 500 submissions. The papers are organized in topical sections on power aware computing, security and fault tolerance, agent and distributed computing, wireless communications, real-time systems, embedded software optimization, embedded systems, multimedia and data management, mobile computing, embedded system design automation, embedded architectures, network protocols, middleware and P2P.