This little robot made by a team of four MSU students creates a vacuum to stick itself to a window and systematically traverse it, cleaning as it goes. With a few revisions to make them lighter and more maneuverable, they could really have something here. I can picture a swarm of them tackling skyscrapers. They could get their power from solar panels on the walls, which they could also clean. If Spirit and Opportunity had a Winboni, they might still be running at full strength.