The value of cultivating microbial strains that are representative of abundant microorganisms in situ is generally acknowledged amongst marine microbial ecologists, primarily because they provide the means to determine phenotypic properties and detailed physiological characteristics of living cells in a controlled setting. In the shadow of the rapid, ongoing expansion in environmental genomic, transcriptomic, and proteomic surveys of marine systems, a minor resurgence in experiments designed to isolate and grow free-living marine microorganisms has met some success. Interestingly, the most immediate impact that many of the resulting strains have had on our understanding of marine microbial communities has not resulted from experiments aimed to interrogate cellular physiology, but rather from their sequenced genomes. It is predicted, however, that their prolonged impact on marine ecology will result from basic laboratory research that links cellular physiology with its molecular underpinnings.