The desktop is a very underused resource on many computers. It often just sits there as a backdrop to files and folders. But using the tool Geektool on OS X the desktop can be put to very good use.
Personally have have a big clock in the lower left corner of my desktop. I have done this by just dragging two shell script boxes from the Geektool application. In these two I run the following two shell commands respectively:
date '+%A, %b. %d' date '+%H:%M'
I use the font Lucida Grande regular and set the font colour to white. For the date I use the size 24pt and for the clock 96pt. I then set the clock to update every ten seconds and the date to update every five minutes. With this I could potentially disable the clock in the menu bar but I have chosen to keep it there for those times that the desktop clock is obscured by windows.
In addition to this I also use this method to display an always up-to-date text based todo list right on the desktop of my various computers.