I have been building my new Arduino DCF77 Master clock for some time now. The clock uses 1" (25mm) Green 7 segment displays, a Yellow LCD display, LEDs and Bluetooth to monitor time, decoding and clock pulses. The clock will drive my various slaves and clock chimes.
Mock up of approx design
The clock has auto display dimming and PIR detection to turn the 7 segment display and LCD back-light on and off when triggered by someone entering the room.
I have also fitted a Blue Tooth board so I can program/update my clock remotely from my Windows PC. The Blue tooth module also means I can read the clock stats and test the PIR detection from my Android mobile.
The DCF77 signal is decoded using the fantastic new DCF77 library written by Udo Klein. See his site here http://blog.blinkenlight.net/experiments/dcf77/dcf77-library/
More details on my clocks progress including test videos here http://home.btconnect.com/brettoliver1/Master_Clock_MK2/Master_Clock_MK2.htm