Mine used to be the generic Windows picture of Stonehenge. Now it’s a picture of Studio 2A at NPR that I took on a recent class trip. I need the motivation. 
Robin
A shot of the Gulf of Mexico I took while my brother and I were trying to fish off one of those rock pier things off the beach in Galveston.
I just changed mine from a picture of Lauren Bacall to the Periodic Table of Elements.
At work, it’s a picture of me and two friends, though it’s starting to bore me.
For my personal laptop, 'tis this Parminder Nagra wallpaper:
Not Safe for Work: http://parminderonline.com/images/dt_bust/POL_dt21_800x600.jpg
Digital Blasphemy. You can thank me later.
My work computer has this picture of Saturn’s moon Enceladus taken by the Cassini probe. Since late 2003, my desktop has been one Cassini snap after another.
My home computer has a little Windows Paintbrush scribble of a smiley face with a tongue sticking out that I made not long after I got my first PC with Windows 3.0 back in the early '90s. I’ve had many computers since then, but the bitmap has been copied over each time and the desktop has remained the same.
At work, I have a directory full of good shots from National Geographic’s Photo of the Day, and I have it set to rotate hourly.
I keep coming back to Smaug
For ages it’s been this pic, “Roots 'n Wings”, from Epilogue.net.
Just changed mine so now it looks like this I also waited 10 minutes for this thread to get to over a page so I wouldn’t be at the bottom of page 1. :o
At home, I don’t use one, it’s just the green Windows background color. But at work, I have a scan of a photo I took back in the '80s, on a Kodak Instamatic camera, of a stunning sunset in the city where I used to live. Everyone who has seen it has commented on how beautiful it is. If anybody wants to see it, I can ask my brother for a bit of temporary web space to post it tonight. Just say so!
I have to ask, when do you ever get to see your desktop?
At work or at home I start up and open all the applications that I will be using. I usually don’t see the desktop again until I log off.
Oh, I saw this Mario 3 desktop and I was wondering how I could make it with the icons as the rocks and stage entrances if possible?
Thanks guys.
OK, I’ve found the wallpaper, and I was wondering if anybody knew how I can make/find a blnk icon so I can change all the icons I want to use in conjunction with the stage entrances blank?
A good point, but I switch around quite a bit, and it’s nice to indulge in a bit ofaesthetic pleasure for those fleeting seconds. Also, one can leave iTunes open and hidden, with the desktop visible, while you’re, I dunno, cleaning your room.
Exactly the site I was going to recommend. I’ve been a paying member there for years. 
Usually my active wallpaper is from Digital Blasphemy, but at the moment I’m using this free image from Mike Bonnell. I just love the colours.
Oh, and I agree with the Webshots recommendations. 
Just remembered: this picture of a sunset in Port Canaveral (Florida) is the wallpaper on my laptop. I took it in January 2003 from the balcony of a cruise ship.
Digital Blasphemy rocks my socks.
Laptop: Picture of the fuzzy little bastards – Juliet in her usual lounging position on my office chair, and Daniel doing his loaf impression next to it. (I like it 'cause it really emphasizes just how big Daniel is)
Main: Fisheye shot of a sunset beach from NationalGeographic.com. Unfortunately, that shot was from 1998, according to the filename, and their archive got trimmed down to 2001 recently, it seems.
Timely thread. I just got a new computer, and I was amused to find that my #1 priority once I got online was to get the same picture I had on my old desktop. I guess I’m really attached to it. I used to switch around a lot, but once I found this one, I stayed with it.
It’s Briscoeteque, from Law & Order: Artistic Intent.