<P>The <EM>Journal of Fluorescence’</EM>s fourth <EM>Who’s Who</EM> directory is to publish the names, contact details, specialty keywords, and a brief description of scientists employing fluorescence methodology and instrumentation in their working lives. In addition, the directory will provide company contact details with a brief list of fluorescence-related products. The directory will be edited by Chris D. Geddes and Joseph R. Lakowicz, editor and founding editor of the <EM>Journal of Fluorescence.</EM></P>