This book constitutes the refereed proceedings of the EUC 2005 workshops held in conjunction with the IFIP International Conference on Embedded and Ubiquitous Computing, EUC 2005, in Nagasaki, Japan in December 2005. The 132 revised full papers presented were carefully reviewed and selected from 352 submissions. Topics covered by the five workshops are ubiquitous intelligence and smart worlds (UISW 2005), network-centric ubiquitous systems (NCUS 2005), security in ubiquitous computing systems (SecUbiq 2005), RFID and ubiquitous sensor networks (USN 2005), and trusted and autonomic ubiquitous and embedded systems (TAUES 2005).