My little piece of Privacy is an installation by Niklas Roy. His workshop is located in an old storefront with a big window facing towards the street. In an attempt to create more privacy inside, Niklas decided to install a small but smart curtain. The curtain is smaller than the window, but an additional surveillance camera and an old laptop provide it with intelligence:

My little piece of Privacy is a robotic curtain which is too small for the window where it is installed. But since it is robotic and controlled by a laptop (running some processing code which does the computer vision), it detects the location of pedestrians outside and positions itself rapidly to where they are, thus not only blocking their looks inside, but also serving as a playful installation for people on the street. The rapid positioning of the curtain is done with a custom linear servo drive. It is basically a DC gearmotor which is controlled by an Atmega, programmed in AVR-GCC (as the Arduino-style-GCC performed to slow to handle the job). Processing code and AVR-GCC code are both on the page for download, as well as plans and schematics for building the linear servo.

Project Page
Album with (even more) hires photos
Download AVR-GCC and Processing codes
Download plans and schematics