I have a nice photo on my Mac desktop, but I never see it because it’s always covered with windows. I see my Android-device wallpaper all the time though, because I’m always hitting the “Home” button. I think this pattern is general and thus mobile is more interesting than desktop on the wallpaper front.
I liked the idea so I made a bunch of themed collections for the same purpose. While I selected things that I thought might work well, I haven’t actually tried them all. Anyhow, if they beautify your phone that’s great, and even if nobody adopts any, I had fun putting the collections together.
I really must say how well-suited Google+ photo galleries are for this sort of thing.