The idea of creating my own cat desktop background came to me after having had cats at home and missing one right now...
So, I created my own wallpaper. I said created because many pictures are not suitable for a background because of their disturbing patterns which "hide" the folders on my desktop.
I prefer "boring" but elegant background which are more "to the point". The color grey is wrongly considered an ugly color. Instead is very much loved by professional designers, photographers...and, yes Adobe (e.g. Adobe Lightroom is all grey color as the standard option)
This is how it look like on my HP laptpop computer I work with.
But you can try making your own wallpers, too. I took the above - original size - picture (Creative Commons rights) from a Flickr fellow member (source) and simply cropped the picture as I wanted. My cropping tutorial with photoshop can be certainly adapted to other image manipulation programms.
Then you can experiment with other sizes and, why not?, be creative as in the example below and which I started from this picture (again in the Creative Common licence) and modified using the cropping tool, the marque tool, the gradient tool with some little dodge tool brushes...
By the way, here is a nice tip for a programm which will I use and will help you browse through millions of images on Flicker. Its a lot of fun!
Here is an Italian website where you can download many images as well. Enjoy it!