This is from a design competition in 2004, where the purpose was to rethink the wall. This wallpaper consisting of four layers of varying grey tones on a bright primary backing. You can remove layers of the pixelnotes, like 'post-its'. According to the designer, Duncan Wilson: "The walls become functional, an integrated noticeboard that documents our activity within the room. Pixelated formations and shapes develop according to our patterns of use." I love this concept and the idea of emerging patterns as people strategically choose where to remove the next piece.
More about Pixelnotes.