If ya gonna use fancy wallpaper do yourself a favour and don't spoil it with those ugly blocks of colour around the Icon captions.
Goto
http://home.attbi.com/~jguerette/transparent/ and download Transparent4 (or search Google for "Guerette transparent") [Jay Guerette is the smart guy who wrote this little gem] Won't mess up any system and doesn't use resources. Turns the text background transparent (choose your text colour wisely, depending on the predominant colour of the image that you are using and where your icons live on it.
And while you're at it, keep icons where you put 'em with Mario Knok's Iconsaver 2.1 from
http://www.core-project.com/iconsaver/index.html also small stable and bug-free.
I know some of them are a bit trite and sticky, but
http://www.lollie.com/ has some good free "inspirational" wallpapers. I liked
http://www.lollie.com/gallery/stormy.html