To reduce the constraints on user activities by user interface equipments, and to support wearable computing requirements, the current work reports the on-going development of a wearable multi-purpose input device. Touch of the fingertip over a ring like finger wearable device is sensed and the touch location and touch pressure information are interpreted to generate the intended command to the host system. Design requirements of single finger operated interface in the context of various applications are analyzed. The selected sensing approaches, sensor element placements and interpretation of user operations are explained. The features of the implemented prototypes are discussed.