Sunlight Director is a heliostat, which was built as part of the Intel Hackathon in New York. The device follows motion of the Sun, and adjust the mirror to make sure that the sun’s rays are always reflected to a predefined spot. This way, the target spot gets the maximum amount of sunlight.
The diagram below illustrates the principle behind the device:
If you are interested in building a similar device, you can follow the construction steps at Instructables.com