DIY watches are quite popular projects. This probably is partially inspired by appearance of smart watches on market. Anyway by making one by yourself you can have all the freedom you want. You can add as many features as you want, and make it look the way you want. Walltech has been experimenting with Arduino based watch where he evolved in to pretty good watch with OLED display.
The watch is based on femtoduino – really small Arduino board. As in all normal watch projects time count is kept on separate RTC chip – DS1307 with backup coin battery. Watch is powered from Lithium Ion battery along with MCP73831 charge controller. Battery ban be charged with on-board USB. 300mAh battery gives 24 hours of watch life. Sleep algorithms makes it run longer. There are several time display modes including analog like, digital, sentence and even bar graphs. There is also an asteroids game to have a little time for yourself when bored. Overall this is great project which it seems is still evolving.