The best widgets, in my view, do one simple thing and do it well. That description would fit Minutes, a great little countdown timer widget. With Minutes you just grab the little blue triangle and spin it around to choose your interval (in whole minutes). When it reaches zero it gives you a Growl notification reading "The time has come" and can also do one of the following:
- Put the computer to sleep
- Stop iTunes
- Start iTunes playing a playlist
- open a file
- repeat the countdown
Minutes is a free download from Nitram+Nunca.