There are several of these tools online, but if you have never tried to look for them... you would never know they were there. This site also allows the user to set up and customize a countdown timer or stopwatch. Better still, you can embed this tool onto your website and even save it to your computer so you can use it when you are not online. Bookmark the link because it is a tool that always comes in handy!
http://www.online-stopwatch.com/
