When Phil Lorimer and I had completed the book for Ellis Horwood over ten years ago we really did feel as though we were contributing to a solid foundation for our chosen field of research in sonochemistry, and so it has proven to be. Sonochemistry has moved on substantially since those days. Most of the major international acoustics meetings now include a component of relating to the applications of power ultrasound in chemistry and processing. Indeed a biennial conference with this title was first launched in Toulouse in 1997 and the European Society of Sonochemistry has had seven major meetings to date. On the one hand research into sonochemistry has expanded in terms of groups involved but on the other there is a tendency to concentrate on areas of particular interest such as sonoluminescence, food technology, nanoparticle synthesis, electrochemistry, environmental protection and, of course, chemistry and chemical processing.