London maker Nick Hall’s Pong clock looks pretty slick, and he includes all the code and schematics so you can make your own.
This project uses the classic video game Pong to tell the time. The 2 players automatically win and lose so their scores reflect the hours and minutes. The clock can also show the time written in words, or with large or small digits. Two buttons allow you to set the time and change the clock mode via a menu screen. The project uses 2 LED matrix panels from Sure Electronics, an Arduino, and a DS1307 clock chip.
In the Maker Shed:
The Monochron is a completely hackable, open source, clock kit that has a funky retro feel. It can be programmed to display several different clock “faces” or you can program you own. The kit comes complete with all electronics (soldering required), laser cut case, and power plug.