I just downloaded Bumptop and I have to say, on first impression, I’m liking it. I watched a demo of a 3-d desktop on ted.com recently, and was amazed by the functionality and fun of it all. Surprisingly, almost all the features shown by the featured speaker on ted are included in this free mac 3-d desktop application. Watch the vid on the site, you’ll see how you can use all four walls and floor for storage, as well as stacking of files. Quite neato.
PS- just discovered in preferences that you can change the wallpaper for all walls and floor. Check in prefs, which you get to from icon on top bar in finder.