A nano-meter is a billionth of a meter and nanotechnology is technology made up of parts that are smaller than the wavelenght of light. Nano-tech means working with individual atoms and molecules and it may be used to build new materials and nano-robots the size of a molecule.
In this video you see a pink droplet of alchohol "finding" its way through a maze to the blue droplet which is a salty solution. This isn't exactly nano but ordinary chemistry: as the blue droplet dissolves, salt molecules spread through the maze and interact with the surface of the alcohol droplet as they reach it. Due to the chemical reactions in the red droplet, this moves towards the still saltier environment until the two droplets meet and mix.
This, of course, does not explanation to why salty foods taste so good with alcohol, but it shows how we can manipulate chemistry to perform intelligent-looking actions and this is what science wil eventually be able to do at the nano level.