Friendly Clock

Friendly Clock is a simple desktop clock for Windows XP and 2000. This analog clock can be moved all across your desktop, but you cannot minimize it to tray.

It isn't too big (just the right size) and you can adjust the transparency percentage as you wish. It also includes a great variety of time formats to choose from, and you can customize the font, color, size, script (Cyrillic or central European) and effects (strikeout or underline). What is more, it allows you to add one alarm, customizing the time and the text you want to display, and you can even set it to execute a file or program. It would be great if it included reminders or a calendar.
Unfortunately, the user interface is not really attractive and looks a bit old, but it is very intuitive and easy to use. You control everything from the menu that appears when pressing the right mouse button on the clock.
All in all, Friendly Clock is a good choice when looking for a simple clock for your desktop, but only if you use any of the two supported versions of Windows. Otherwise, it won't work.