ZBar is an open source software suite for reading bar codes from various sources, such as video streams, image files and raw intensity sensors. It supports many popular symbologies (types of bar codes) including EAN-13/UPC-A, UPC-E, EAN-8, Code 128, Code 39 and Interleaved 2 of 5.
The webcollage program pulls random image off of the World Wide Web and scatters them on the root window. One satisfied customer described it as "a nonstop pop culture brainbath." This program finds its images by doing random web searches, and extracting images from the returned pages.