This morning, Daring Fireball linked to a great article called Who Watches the Watchmen. It is about the design of watchclocks — devices that date back to the early 1900s that ensure that watchmen are correctly making their rounds. It is a punch-clock-like system with the steampunk equivalent of GPS (encoded into similar keys with different teeth.) I had heard of watchclocks before, but never really dug into how they work, so it was interesting to see their use detailed and a picture of one of the paper discs. The article then uses the idea of watchclocks to springboard (briefly) into interface design and game level design. I am not sure how much I can summarize here without just reprinting the whole article, so go read it yourself if you have any interest in such things.