The major lesson from the 8th International Conference on the Cell and Molecular Biology of Chlamydomonas held at Lake Tahoe June 2-7, 1998, is that chis unicellular alga is emerging more and more as a powerful model system for studying a wide range of important biological processes. These processes include photosynthesis, phototaxis, flagellar function and assembly, gametogenesis, mating, cell wall synthesis, and chloroplast biogenesis. Among its many attractive features, Chlamydomonas is amenable to extensive genetic analysis, and many mutants affected in photosynthetic activity and flagellar movement have been isolated. Both flagellar and photosynthetic functions are dispensable in this alga under appropriate growth conditions, which greatly facilitate the use of genetic approaches. In addition, transformation systems for all three of the Chlamydomonas genomes - nuclear, chloroplast, and mitochondrial - have been developed; Chlamydomonas is the only organism for which this capacity presently exists.