Clock using Arduino and a Freetronics DMD display.
I took one of my Ardev boards with its Real Time Clock and Temperature sensor and combined it with Two Freetronics DMD LED Displays. I also added a $15 bluetooth to serial board. By connecting via bluetooth with your smart phone bluetooth serial app, you can see the output of the clock and send it commands to change the time and bring up some info screens.
The Help page is display when you send “!” to the bluetooth port via your smart phone.