In Facebook I have downloaded all friends avatars. The avatars were then processed by me using a modified Processing script. The script it basically generates half tones and saves the images back.
I then uploaded all images onto Facebook making it possible for all my friends to access their processes avatar and use it for free as their new avatar. The gallery at Facebook is called "Facewall". This gallery is non public and could only be accessed by fb friends of mine.
I later will print some of the proceessed avatars in a 2-color version on black 3.5" floppy disks, creating a real Facewall series.