Word Clock is a typographic screen-saver for Windows and Mac OS X. It displays a fixed list of all numbers and words sufficient to express any possible date and time as a sentence. Word Clock displays time by highlighting appropriate words as each second passes.
There are two display modes; linear block of text and rotary which has a nice relationship with traditional analogue clocks.
Here is a video of the screen-saver clock running, showing both rotary and linear modes:
Word Clock is written by Simon Heys.
Head over to Simon's site http://www.simonheys.com/wordclock/ and grab yourself a copy now.