Random access memories or RAMs form an important part of a computer. M Reed and his collaborators at the Yale University, USA, have built molecular switches which could be used for storing data. These switches consist of rod-like carbon based molecules that can carry a current between two gold electrodes. The molecules do not conduct electricity but can be made into good conductors by applying a voltage to the electrodes. Thus they behave like a two-state system with a on and off state, a basic criterion for a memory device which stores information in zero for switch off and one for switch on ( Applied Physics Letters , Vol 78, p3735).