I changed my Twitter background. It’s a photo I took of the Saco Heath Preserve in the summer of 2007.
I tried many times to get a screenshot without any protected tweets. When I saw this I grabbed it quickly.
I use dimensions of 1600 pixels wide and a sidebar of 250 pixels wide. I then fade the right and bottom of the picture to a solid color and set the background to that color, for those people with large and wide-screen monitors.