There has been a rapid growth in ubiquitous systems research in networking environments during the past few years. Many novel architectures, protocols, algorithms, and applications have been proposed, implemented, and evaluated. The issues and challenges for the development of such technologies not only encompass a broad spectrum of research topics but also involve envision new multi-disciplinary applications that will change the way in which we live and work. The goal of this e-book is to bring to the attention of the readers some the latest technical developments and state-of-the-art research results in the fast moving field of ubiquitous computing. For this e-book, we have selected papers that focus on two main themes that have direct impact on ubiquitous computing. The first theme deals with wireless, ad hoc and sensor networking issues while the second theme deals with middleware and other pervasive technologies that support ubiquitous services.