I do something similar on my Mac, but in screen saver mode, with the images changing every few seconds. I like seeing that when I return to the computer after not using it for 15 minutes or whatever the threshold is. Plus, I can initiate it any time using the "sleep corner" thing. Sometimes I like to run that when I'm at the computer, but doing something other than actually using it (like eating). When I am using the computer, I generally can't see 90% of the desktop image anyway, so I'm wondering whether having the desktop image changing would be as interesting. Typically the only situation where I really take the time to look at my desktop image is briefly, when I'm waiting for the computer to shut down.
Being completely neurotic, I minimize/maximize windows constantly as I change between tasks. Sometimes just to peek at the image that's up. Right now it's that great B&W candid shot of Mingus in a trenchcoat with a pipe in his mouth, escorting his gorgeous wife.