This is a bit off-topic, but since someone mentioned spiral staircases ... My grandfather was a carpenter, and apparently he was rather good at staircases. He left us a scale model of a spiral staircase, which is very nice - though it is collecting dust in my parents' attic, I'm afraid. Also a scale model of a big ocean steamer (S.S. Oranje) that he built from scrap pieces - this was in the depression years, when he was out of a job and money was short - nothing short of amazing. Plus he built a mandolin, which isn't tremendously playable but has a nice butterfly inlay near the soundhole (a la Gibson) and a 6 string banjo. There's also a violin lying around somewhere, but I'm guessing that was bought in a shop.