Things that don't work are much more intriguing than things that do. At least, that's the premise of the Revealing Errors blog, a site devoted to those moments when a gust of wind disturbs the curtain and you catch a tantalising glimpse of a flustered little man frantically pulling levers.
Here a garbled shopping receipt will teach you about the concept of interpolation, a sideways error message will show you how to buy a long thin display screen when only short wide ones are readily available, and where in the world you might be if your mobile phone thinks you're in a town called "bucklame".