A simple but useful option available in Windows 7, which many may not be aware of, is the ability to display up to 2 additional time zones via the System Tray Clock. Living in Oz and continually battling the time differences, I have found this to be particularly helpful.
Left click on the time display in the System Tray and select “Change date and time settings” or right click on the time display and select Adjust date/time:
Now click on the tab for Additional Clocks. Place a checkmark in the little box next to “Show this clock” and then select the appropriate time zone. Give the clock a suitable name and when all finished click Apply, OK:
Hover your mouse cursor over the system tray time display and you will now see this:
Left click the time display to see this: