PerfectClock is a powerful and user-friendly application that allows you to have multiple skinnable world time clocks on your desktop.
The program is fully customizable and sits silently on your system tray from where you can command everything. It allows you to have as many time zones as you require, all with different funny clocks (digital, analog and calendars), offering the possibility of adding customized labels for easy identification, as well as other features such as transparency, shadow, font color, and post-processing options including hue, saturation, brightness, contrast, etc. You can set each clock to be visible, stay on top, grouped, locked, placed in system tray, and click though. It also includes many professionally designed Wallpapers Clocks, which can also be used as a screen saver, and also a lot of alarms and reminders, that will help you remember important events. The user interface is really intuitive and simple, and is available in multiple languages. Without a doubt PerfectClock is the most comprehensive and powerful program of the like, I would definitely recommend it to you.
It supports Windows 2000/XP/Vista.
I don't see any point in buying this program as there are a variety of other similar programs for free.