Model organisms have been used over a century to understand basic, conserved biological processes. The study of these experimental systems began with genetics and development, moved into molecular and cellular biology, and most recently propelled into functional genomics and proteomics. The goal of this review is simple: to discuss the place of model organisms in "The Age of the Ome": the genome, the transcriptome, and the proteome. This review will address the following questions. What exactly is a model organism? What characteristics make an excellent model system? Using the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans as examples, this review will discuss these issues with the aim of demonstrating how model organisms remain indispensable scientific tools for understanding complex biological pathways and human disease.