Eltima Software has introduced Clox 1.0 (http://mac.eltima.com/desktop-clock.html) for Mac OS X (10.6.6 or higher). It costs US$0.99 and is available worldwide exclusively through the Mac App Store in the Lifestyle category.
Clox adds a clock to the desktop with individual settings like opacity, always on top and click-through mode, customizable size, 12/24 hour display and more. Each clock can have its unique name and place on the desktop.