As the genomes of many organisms have been sequenced, a variety of global analyses, called 'omics,' have been initiated. Cloning of the set of all open reading frames encoded by the genome (ORFeome) of an organism is a major challenge, which serves as an indispensable provision before one launches into the ocean of the postgenomic world. A suitable strategy for high-throughput cloning and expression of thousands of genes is crucial to success. Recently developed systems employing site-specific or homologous recombination have made it feasible to manipulate thousands of ORFs en masse. Using these technologies, several recent studies have successfully fished biologically active small molecules and target proteins out of this bountiful ocean.