My patio. It was wet. I thought it would make a good desktop background.
This image is free and I’m releasing it in to the public domain. I took a 2560 x 1024 pixel slice out of it to use as dual monitor wallpaper, and of course you’re free to resize it to 1600 x 1200, 1280 x 1024, 1024 x 768, or etc x etc.
(An advantage of dual monitors I’ve found in GNU/Linux is that you can have a wallpaper that stretches across two displays. In Windows–by default at least, and no easy way to configure otherwise–I was only able to have an image repeated on both displays.)