No need to download and install third party utilities to display multiple clocks in Vista. Here are the steps to display multiple watch
- Click on time in System tray
- Click on "Change date and time settings..."
- Click on "Additional Clocks" tab
- Enable additional clocks by checking "Show this clock" checkbox
- Select the timezone for the clock, and click OK
Hover over the time on system tray and now you will see time from second watch as well :)