An
alphanumeric keyboard that is easy to learn, easy to use, and mountable on a
handset for one-hand operation, comprises a
virtual clock face having the center for the rotation of virtual hands, first set of twelve hourly radial positions, from one o'
clock to twelve o'
clock, surrounding the center, second set of twelve hourly radial positions, from one o'
clock to twelve o'clock, surrounding the center and nearer to the center than the first set of twelve hourly radial positions, twenty four key areas, each key area being uniquely associated with one hourly
radial position of the first and second sets, wherein each key area is substantially of 30 degree annular sector shape and contiguous to the adjacent key areas associated with the adjacent hourly radial positions, wherein all twenty four key areas are substantially of equal area, at least thirteen alphabetic keys placed at predetermined hourly radial positions of the first and second sets, and wherein each key has an indicia surface that is within the associated key area for being pressed by a finger. The associated radial direction or time may be marked on the key surface for visual or tactile differentiation.