This is my self-made straw man.
I change my wallpaper more often than I change my sig.
Check this out. Everlasting wonder and awe.
A baobab tree in native landscape.
How do you do that with the links and widgets? Is it just Active Desktop, or is it a Vista only method?
With all of the Obama locations on this board, I’m surprised I’m the only one whose wallpaper looks like this. Unless maybe there’s one I didn’t click on.
I use the XP PowerToy Wallpaper Changer to rotate wallpapers on my XP machines. Landru has various pictures I have taken, Albus has last month’s Mutts strips, and Ziggy has Quantum Leap-related screen shots and various NASA imagery. M5, my Ubuntu Linux box uses one of Ubuntu 7.10’s default wallpapers. It’s the darker one with the swirlies. My 5th PC, HAL9000, doesn’t have wallpaper set up on either its Win3.1 or its Win98 partitions.
A picture of a brain splicing psycho evil killer. And some guy on the left. 
Link to my basic Mac blue swoosh with a Pearl Jam stick-man
it is active desktop. you need a .css file and an html file. you cant do it on vista. its pretty straight forward. i can send you the files
http://despair.com/gettowork.html
I rotate through several of the Demotivators this is the current one.
This naked&angry pattern (altered to have a darker background.) The site’s a great source for tiled backgrounds.
I’ve had this one since May 2007, when my wife and I took a helicopter ride to the bottom of the Grand Canyon.
I created a couple wallpapers from the webcomic Erfworld (with the approval of the creators). I currently use this one for my widescreen desktop at home and this one for the vertical monitors at work (since it’s the most visually interesting vertically-oriented panel, if one excludes ones that wouldn’t go over very well at the office).
Is it just me, or is the picture gone to 404-Land?
ZOMG THAT MEANS HE IS RIGHT BEHIND YOU WITH A KNIFE BUT DON’T LOOK NOW BECAUSE THAT WILL JUST PISS HIM OFF!
Actually, I got a 404 on that one too. 
Sunshine After the Rain (direct download link), from the KDE packages.
(And, for the record, my window manager is Window Maker, but KDE seems to have all of the good applications (compared to Gnome), so I end up with KDE-centric distros (Kubuntu 8.04.1, right now) and, thus, the kinds of background images KDE provides.)
I have my daughter staring accusingly out of my desktop at me
I’ve got this wallpaper someone made featuring Portal’s infamous weighted companion cube. Oh, companion cube. How I miss you so.
Aperture Science: We do what we must, because we can.
They’re pretty BSG-heavy at the moment. At work I have the final shot of “Revelations.” At home I have the final shot of S3 on one monitor and couple pictures of this Suicide Girl (SFW) from a different photoset (also SFW).