This is the third volume in the Reviews in Fluorescence series. To date, two volumes have been both published and well received by the scientific community. Several book reviews have also favorably described the series as an "excellent compilation of material which is well balanced from authors in both the US and Europe". Of particular mention we note the recent book review in JACS by Gary Baker, Los Alamos. In this 3rd volume we continue the tradition of publishing leading edge and timely articles from authors around the world. We hope you find this volume as useful as past volumes, which promises to be just as diverse with regard to content. Finally, in closing, we would like to thank Dr Kadir Asian for the typesetting of the entire volume and our counterparts at Springer, New York, for its timely publication. Professor Chris D. Geddes Professor Joseph R. Lakowicz August 20*^ 2005.
