Genetic information is being uncovered quickly and in vast amounts through the largely automated sequencing of genomes from all kinds of organisms. As this information becomes available, enormous challenges are emerging on three levels: first, functions will have to be assigned to individual gene products; second, factors that influence the expression level of these gene products will have to be identified; and third, allelic variants that act alone or in combination to give rise to complex traits will have to be characterized. Because of the sheer size of genomes, methods that can streamline or automate these processes are highly desirable. Fluorescence is an attractive readout for such high-throughput tasks because of the availability of equipment designed to detect light-emitting compounds with great speed and high capacity. The following is an overview of the achievements and potential of fluorescence resonance energy transfer (FRET) as applied in three areas of genomics: the identification of single-nucleotide polymorphisms, the detection of protein-protein interactions, and the genomewide analysis of regulatory sequences.