Proof-of-concept interface design project from MIT Tangible Media Group demonstrates a system combining the use of a smartphone with a desktop computer - video embedded below:
THAW is a novel interaction system that allows a collocated large display and small handheld devices to seamlessly work together. The smartphone acts both as a physical interface and as an additional graphics layer for near-surface interaction on a computer screen. Our system enables accurate position tracking of a smartphone placed on or over any screen by displaying a 2D color pattern that is captured using the smartphone’s back-facing camera. The proposed technique can be implemented on existing devices without the need for additional hardware.