XNote Stopwatch - Try the most feature-rich stopwatch and timer software on the net for free!
Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Gestimer - For those little reminders during the day
Stopwatch - A Java countdown timer and stopwatch. Features a fullscreen and a resizable window mode.
Stopwatch - yeahit - Minimal stopwatch
TimeLeft - TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock...