In all eukaryotic cells, vesicular trafficking is crucial for maintaining cellular and organelle functions. RABs and SNAREs play key roles in vesicle/organelle identity and exchange. Budding yeast genetics and mammalian cell biochemistry were the most effective approaches for investigating molecular mechanisms underlying vesicular trafficking and remain important in exploring new horizons. The field of vesicular trafficking attracted plant biologists in the early 1990s. Today, this field continues to stimulate a wide range of research. This review starts with some history of RAB and SNARE research in yeast and mammals and introduces a widely accepted general model. Then we summarize recent reports regarding plant RABs and SNAREs, focusing on functional diversity. Finally, we discuss how plants assign new roles to conserved vesicular trafficking proteins to perform divergent, higher order plant functions. Plants have apparently evolved a unique set of plant-specific RAB and SNARE molecules that play significant roles in plant life.