Your desktop doesn't have to be a modern marvel of technological science. Instead, you can bring back a little bit of the past like Ryan Meek did in today's featured desktop.
Ryan explains how he got the date and time in the magic mirror using Geektool for Mac OS X:
This is my current desktop using Geektool with my png overlay for a dirty mirror effect above the geeklets, Dragthing with my custom theme and custom wallpaper/icons. The banners roll down and up as needed and function as docks. The mirror displays time and date and has a functioning analogue clock.
For more info, source files, and a full how-to, Ryan's provided everything on his web site.