Behind-the-display interaction has gained popularity for interactions on handheld devices as researchers have demonstrated the viability of such interactions on small devices. However, most designs have investigated the use of direct input behind the screen. We demonstrate that behind-the-display interaction with cursor input is promising and can be a useful augmentation to handheld devices. We developed a prototypical system on a PDA to which we affixed a wireless mouse. The mouse is mounted on the rear of the PDA with the optical sensor facing outwards. The system is designed to be used with one hand, and prevents occlusion and finger-reach. Through several applications we propose the benefits associated with behind-the-display cursor interaction. A preliminary user evaluation indicates that users can benefit from such an interaction when operating a handheld using one hand.
