This is the Vertwaker, an autonomous wall-crawling robot that also happens to be an artist. Shaped a bit like the noble Roomba, Vertwalker is less concerned with sweeping up our messes than it is with creating a few of its own. Just stick it to a wall, arm it with its weapon of choice (a marker), and in due time you'll have a unique work of art.
Lightweight when compared to a robotic vacuum, the Vertwalker is made primarily of foam boards with a few sensors thrown in to keep it from falling off the wall or running into the ceiling. The current Vertwalker is actually a third-generation prototype; its predecessors having been exhibited in Germany and Jerusalem. To catch a glimpse of the Vertwalker creating its works of art, you can either head on over to the Saatchi gallery in London, where it will be on exhibit until September first, or you can just watch it do its thing in the video below.