Modern electronics is being transformed as device size decreases to a size where the dimensions are significantly smaller than the constituent electron's mean free path. In such systems the electron motion is strongly confined resulting in dramatic changes of behaviour compared to the bulk. This book introduces the physics and applications of transport in such mesoscopic and nanoscale electronic systems and devices. The behaviour of these novel devices is influenced by numerous effects not seen in bulk semiconductors, such as the Aharonov-Bohm Effect, disorder and localization, energy quantization, electron wave interference, spin splitting, tunnelling and the quantum hall effect to name a few. Including coverage of recent developments, and with a chapter on carbon-based nanoelectronics, this book will provide a good course text for advanced students or as a handy reference for researchers or those entering this interdisciplinary area.