SideSight expands the multi-touch capabilities of small mobile devices beyond the screen. Infrared sensors embedded along each side of device are capable of detecting the presence and position of fingers within the proximity of the device. When the device is rested on a flat surface, such as a table, the user can carry out single and multi-touch gestures using the space around the device. This gives a larger input space than would otherwise be possible, and which may be used in conjunction with,
- Alex Butler, Shahram Izadi, and Steve Hodges, SideSight: multi-"touch" interaction around small devices, in Proceedings of the ACM Symposium on User Interface Software and Technology (UIST '08), Association for Computing Machinery, Inc., October 2008.