Throughout the ages man has moved towards smaller and sleeker technology. The ideas stated in Richard Feynman’s classic of the late 1950s “There is plenty of room at the bottom” are finally materializing under the name of ‘Nanotechnology’. Nanocomputing is a major aspect of this new advancement. Nanocomputing essentially involves carrying out computational functions, which are presently being carried out on micro scale, on a much more compact and sophisticated nanoscale. Concepts of electrical and electronic engineering, quantum mechanics and other related fields are applied to different molecular entities. The tremendous storage and processing capabilities of biological molecules such as DNA, RNA are harnessed. Organic molecules such as Rotaxane and polyphenylene are also used owing to the special characteristics offered by them. In this paper, we analyze the some of the most striking methods of fabrication of various basic electronic and computational entities such as logic gates, flip-flops, and rectifying diodes can be achieved at the molecular level making use of individual molecules themselves, as hardware. Finally, we review the various possible applications of these ‘Nanocomputers’ in fields right from developing cellular robots to preventing environmental pollution.