XNote Stopwatch - Try the most feature-rich stopwatch and timer software on the net for free!
ClocX - ClocX - freeware analog clock for Windows desktop with many features like calendar, alarms, skins, antialiasing and transparency.
Gestimer - For those little reminders during the day
LClock - Longhorn systray clock program
Stopwatch - yeahit - Minimal stopwatch
DS Clock - Keep your time synchronized with Atomic Time servers, using customizable digital desktop clock with westminster chimes.