This is a Digital Clock that I am working on.

Currently there is the main digit plate, with holes for 38 LEDs (9 per digit plus 2 for the colon).

I decided to multiplex the LEDs. I get decent brightness, but I used 330 ohm resistors. Use 220 Ohms with white LEDs.

LED Test video: http://www.youtube.com/watch?v=aNAoDoVr2t0

Designed in SketchUp, this clock is still a work in progress.

Attached is a Fritzing Diagram. that is the wiring for the LEDs and Arduino. It is still incomplete, as it doesn;t include RTC module, input devices, Power, and a buzzer or possibly a sound module.

keep watching, there's more to follow...