For Windows users your desktop can be like your house. Some people keep it ridiculously clean, some people are hoarders and most of us are somewhere in between. As a support person I see a lot of desktops and sometimes I cringe as I look for an AutoCAD or Revit Icon over two monitor full of icons for who knows what.
A friend of mine, Todd Behning recently turned me on to Stardock Fences. This program can group your desktop icon together in logical groups that you can create. It has another interesting feature that hides selected groups when you double click on your desktop. It's a total geek thing, but I am loving the fences.