A method comprising: receiving an indication of a portion of a thumb being placed on the surface of a capacitive input pad, the capacitive input pad having a plurality of sensing cells arranged near the surface in a closely-spaced configuration; receiving a respective capacitive value associated with each respective sensing cell of the plurality of sensing cells, the capacitive value having a defined relation to the proximity of the thumb to the respective sensing cell; comparing the capacitive value for each sensing cell of the plurality of sensing cells to a first predetermined threshold value and to a second predetermined threshold value; storing the results of the comparison; identifying from the results of the comparison a contact region corresponding to a first set of the plurality of sensing cells having a capacitive value greater than the first predetermined threshold value, a shadow region (30a,30b) corresponding to a second set of the plurality of sensing cells, each sensing cell of the second plurality having a capacitive value less than the first predetermined threshold and greater than the second predetermined threshold value, the second predetermined threshold value being less than the first predetermined threshold value, and a third set of the plurality of sensing cells, each sensing cell of the third plurality having a capacitive value less than the second predetermined threshold; outputting an indication of the first set of the plurality of sensing cells, the second set of the plurality of sensing cells and the third set of the plurality of sensing cells; and determining whether a left thumb or a right thumb is in contact with the capacitive input pad based on characteristics of the shape of the shadow region relative to the orientation of the capacitive input pad. receiving an indication of a portion of a thumb being placed on the surface of a capacitive input pad, the capacitive input pad having a plurality of sensing cells arranged near the surface in a closely-spaced configuration; receiving a respective capacitive value associated with each respective sensing cell of the plurality of sensing cells, the capacitive value having a defined relation to the proximity of the thumb to the respective sensing cell; comparing the capacitive value for each sensing cell of the plurality of sensing cells to a first predetermined threshold value and to a second predetermined threshold value; storing the results of the comparison; identifying from the results of the comparison a contact region corresponding to a first set of the plurality of sensing cells having a capacitive value greater than the first predetermined threshold value, a shadow region (30a,30b) corresponding to a second set of the plurality of sensing cells, each sensing cell of the second plurality having a capacitive value less than the first predetermined threshold and greater than the second predetermined threshold value, the second predetermined threshold value being less than the first predetermined threshold value, and a third set of the plurality of sensing cells, each sensing cell of the third plurality having a capacitive value less than the second predetermined threshold; a contact region corresponding to a first set of the plurality of sensing cells having a capacitive value greater than the first predetermined threshold value, a shadow region (30a,30b) corresponding to a second set of the plurality of sensing cells, each sensing cell of the second plurality having a capacitive value less than the first predetermined threshold and greater than the second predetermined threshold value, the second predetermined threshold value being less than the first predetermined threshold value, and a third set of the plurality of sensing cells, each sensing cell of the third plurality having a capacitive value less than the second predetermined threshold; outputting an indication of the first set of the plurality of sensing cells, the second set of the plurality of sensing cells and the third set of the plurality of sensing cells; and determining whether a left thumb or a right thumb is in contact with the capacitive input pad based on characteristics of the shape of the shadow region relative to the orientation of the capacitive input pad.