Quote from Pusikas »
There is Hourglass as well, which is very lightweight, iirc. So lightweight that you have to edit .lua files to configure it. :)
There are more AddOns that track Cooldowns... DoTimer comes to mind.
Th coolDown Version in Valle's link is a lot older than the one to be found on http://files.wowace.com. No idea what was changed / added, tho.