Hello everyone; I was looking for this project for a long time. Finally I it it together with a lot of effort. For this project you will need:
1- Arduino Uno ($30 from Radio Shack)
2- RTC DS1307 (like $2 from EBay)
3- 2 Shift Registers 74HC595 (like $1 eachh from Ebay)
4- 16 leds
5- 16 330 hom resistors
The clock will display the hours using the first 4 leds, then the minutes using the next 6 leds and finally the seconds using the las 6 leds.
There is a better explanation from the original project here (as well as other cool projects): http://www.multiwingspan.co.uk/arduino.php?page=bclock