Why atypical? Well, besides the fact that it's a bit more accessible and attractive than Windows' clock, LAVClock is also an astrological clock, a lunar calendar, and a constant source of information for all astrology fans.
The program works as a substitute for Windows' clock and it features many customization options. You can also choose which information you want the clock to display, enter dates of birth to know that the planets have to say about people born on that day (in English, mind you), take a look at different lunar calendars, or know the exact position of the planets with the Solar System.
Apart from this, LAVClock also works as a regular clock, letting you set alarms and checking the normal, everyday calendar. So, if you're interested in theories concerning horoscopes and planetary positions, this might a very interesting complement to the desktop of your PC.
30-day trial version.