This will create a nice JS clock. You can change the color of it too.
Place a digital clock on your Web page!
Creating a Clock
Say Hello to HTML5 Web Worker
Visitor time visiting the page
Shows how long the user have been in the website and clock each second and shows it in a text box.
Hours, minutes and seconds java script clock, with the twist that the time is displayed in binary! An unusual script, that gives a nice twist to the standard java script clock. The only down side is that you need to understand binary to read the time.