I think
OmniCC will replace the spiral timers on all your bars with numeric counters. I haven't used it in a while, but I believe it is still maintained and works with any addon that includes some sort of timer model.
I previously use it with a faded, click-thru bartender bar to keep all my cooldowns in a convenient area to monitor, but have switched to Powerauras.
<3 Powerauras, especially for abilities with longer cds like PI and PS. For the shorter ones like Penance and CoH, I normally am relying on my inner clock and really don't need a timer. For things like Serendipity and Trinket procs, I have color-coded text notifications. i.e. 'Serendipity 1' in red for first stack, 'Serendipity 2' in yellow and 'Serendipity 3' in green for a full stack.
*edit Not sure which is more amazing, that I misspelled Serendipity three times, or that I actually spelled it right once.
Edited, Jan 13th 2010 6:21pm by Trylofer