This is a year or so old now, but I though you might like to feature it. It’s a clock that plays the game pong to tell the time. It uses a couple of cheap LED matrix panels an Arduino and clock chip.
As the author says, all the instructions are on the [website],
“..and quite a few people have build them / modified my code to add other features.”
We hope they will submit their “mod”, I would be glad to post them in the blog.