Secretory and glandular trichomes (SGTs) populate the aerial surfaces of approximately 30% of all vascular plant species. These uni- and multi-cellular appendages are proposed to play a critical role in plant protection against various biotic and abiotic stresses including herbivore attack, pathogen infection, extreme temperature, and excessive light. One of the most remarkable features of SGTs is their capacity to synthesize, store, and secrete large amounts of secondary metabolites. Because they are not essential for plant viability, SGTs provide a unique opportunity to study complex and specialized metabolic pathways that operate within the confines of a simple and highly accessible developmental structure. It is noteworthy that many trichome-borne compounds have significant commercial value as pharmaceuticals, fragrances, food additives, and natural pesticides. For this reason, the prospect of exploiting SGTs as “chemical factories” to produce high-value plant products has recently captured the attention of plant biochemists and biotechnologists alike. Realization of this goal will be facilitated by genome-scale research focused on the identification of genes that control the development and biochemical functions of SGTs.