As part of a larger project I've been playing with a clock chip and a sure electronics matrix. I then realised I could use a relay to add a ticking sound to it, and lo! A very annoying clock :) http://www.youtube.com/v/tLJa6T9MDhk&hl=en&fs=1 (sorry for the particularly poor video quality, I'm using an old camera at the moment).
I've got a few more relays on order, I might add one per digit/couple of digits.
The code and hardware aren't anything special, but if anyone would like to see a schematic or the code let me know.