If you’re looking for a simple no-frills countdown timer, Timerr is a web-based solution that’s as easy to use as setting a physical kitchen timer.
If you can twist the knob on a real kitchen timer you can use Timerr. Visit the site, use your mouse to turn the knob, and click the start button. Timerr counts down and sounds an alarm when the set time period has elapsed–it’s a dead simple timer with a nice visual overlaid. For another great timer with a simple web interface (as well as a downloadable Adobe Air-based version) check out previously reviewed Focus Booster.