XNote Stopwatch - Try the most feature-rich stopwatch and timer software on the net for free!
Gestimer - For those little reminders during the day
Timer for Mac - Timer is a complete and professional stopwatch, alarm clock, timer and clock utility for Mac.
Stopwatch - yeahit - Minimal stopwatch
Stopwatch - A Java countdown timer and stopwatch. Features a fullscreen and a resizable window mode.
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.