Diatoms are single cells that can be regarded as nature's unique nanofabrication factories. They are “nanobioreactors” producing an extraordinary diversity of patterns and structures on their silica shells that can be used for synthesizing fascinating products. The nanostructured surface of diatoms serves as a template for the formation of biomimetic patterns from the nanoscale up to the microscale through various lithographic techniques. The resultant biologically inspired nanostructures can be further used as biosensors in explosives detection, and biomedical and optical devices etc. The surface of the silica of both living and fossilised diatoms can also be doped with a variety of oxides, metals and polymers for use in photovoltaic solar cells, lubricants, paints and pharmaceutical drug delivery carriers. Extant since the Jurassic era, diatoms are a major source of crude oil. Living diatoms can be used to produce biofuel. Construction of devices that milk diatoms without sacrificing them may make it possible to construct diatom solar panels (DSPs) to generate oil.