Found a wicked site tonight. Mandolux.com. It's from a guy named Mando Gomez who's a photographer that has created desktop images for people with multiple computer monitors.
At home, I am blessed with two honkin' 19" LCDs on my main computer. It's awesome - dragging windows onto both screens and truly being able to multitask.
Now, I've cropped and placed some of my own images onto my screens, but for those not fortunate enough to have their own, check out Mandolux.com. The archive section of the site has plenty of cool images to use.
P.S. I would show you some images from Mandolux.com but Mando gets a bit upset with bandwidth hogs.