I can't show mine at home. I usually have something highly erotic on it.
A few years ago there was a guy that took a screencap of his desktop to show it off to other users on a forum. He forgot to remove the "Shemale Porn" folder from his desktop before he did it. Hilarity ensued.
I just keep everything I use running all the time. ...snip...
Typical load, from right to left:
Newb. :) I have to toss my taskbar up on the left or right side of my screen to keep it readable. Right now I've got (top down): IE, shortcut to GodMod on Windows 7, Remote Desktop quick launch, command prompt quick launch, WinScp quick launch, Winamp, TweetDeck, Messenger (two windows), Excel (four windows), Outlook, Notepad, Access, Word, Chrome, Gtalk (two windows), random explorer window, and Foxit PDF Reader.
Windows has had something similar (taskbar) for a long, long time, but the Windows 7 version is more flexible/useful.
The Windows Vista/7 taskbar additions are a direct rip from OS X's dock. Other rather blatant rip-offs were the Widgets (Dashboard in OS X) and the search feature on the Start menu (Spotlight in OS X).
As for the original question (re: desktop) I use it as my crapping ground. I never launch programs from it so random files that I'm copying for an install or whatever live there. Every 2-3 months I clean it up and start over.