We propose a projection-based wearable system, "PALMbit", which enables user's palms to input control events and to output graphic information. The I/O interface for wearable computers depends largely on their practical applications. In the proposed system, we developed both an input and output method for controlling digital appliances; an optical projection onto the user's palm, which is registered by image processing, and a gesture interface based on finger actions. By projecting an image of a virtual remote controller onto the user's palm, the user is able to control digital equipment in...