Measurement of fluorescence light emission provides the basis for many analysis techniques in the life and physical sciences and for environmental monitoring. The fluorescence spectrum, i.e., a plot of intensity as a function of wavelength, is the usual data format. The fluorescence decay represents an independent type of "spectrum," wherein the intensity is measured as a function of the time interval after an excitation pulse. The term fluorescence lifetime refers to the characteristic time constant (or equivalently, the inverse of the rate constant) for the decay. Fluorescence decay/lifetime data are extremely valuable because they directly reflect a molecular property. For example, the intensity of the excitation source can drift considerably without affecting the accuracy or precision of the fluorescence lifetime. My presentation will introduce you to the two traditional means to study fluorescence decay, before I describe DTI's approach, which can generate high quality data 100-1000 times faster. Data recently collected at DTI will give you a feel for the important hardware and data analysis issues. I will also comment on some of the economic issues that are important for commercialization of the technology.