I had the idea of making a broken 7-segment display clock after walking past one every morning, getting off my train at London bridge. There's something interesting about the unfamiliar symbols, and it's vaguely reminiscent of the self-destruct device in Predator.
This is the result. It is kind of pointless but it looks quite cool in my biased opinion. Clicking on the clock gives you the real time, which is arguably more useful.
Feel free to download the source code. Sorry it's not on GitHub, I'm not down with the cool kids yet.
UPDATED: You can find the code here on GitHub