So, I used to work for a company that made rapid prototyping machines...you can think of them as 3D printers. Here are some photos of mistakes from a process that takes the same idea and writes it large -- machines that extrude concrete to make buildings.
I don't know what to think about these photos. They seem to show the houses as if suspended on steel cables in midair...which seems impossible. One page I looked at seemed to imply that these were just computer visualizations of the bad results, but the original source page says that elderly people are currently living in these houses...saying that the houses were built wrong and then put to a charitable use.
Real or not, though, these grotesque abortions of the extrusion process are quite amazing to look at.