Field of Flowers
The "wallpaper" is currently a girl's head, peeping out of a large field of bright yellow flowers. When I once did a presentation to some bio-medical people, they didn't seem to see the beauty of the scene: they wondered why the girl wasn't sneezing and then talked about pollen allergies!
The screensaver is currently a collection of photos of people I know and places I have visited. Every so often, I'll add a few and (less often) remove some. They are quite hypnotic, once they begin! Others quite enjoy them, too!