Hear! Hear! Most of my desktop backgrounds come www.nasa.gov's image gallery. The current one in use is titled "Sunrise over Mars", taken by one of the rovers.
BTW for the curious:
I tried to find it on NASA's image gallery, and failed(was going to link to it).
A Google image search for that title found it.
That image blew my socks off! Wow! A picture from Mars I can relate to! I've seen many sunrises from good old planet Earth, but from another planet?!?!? It gives me goose bumps!
Speaking of which, I've been looking all over for a high resolution version of that beautiful image. Would you mind posting it somewhere to share?