Its just a background! I'm shit at the icons, I use the ones what come with sitwulf's theme (skin). You can get his skin from www.symbianware.com (its in the slauncher screenshots section).
Here are some cool pics which you can use as backgrounds for slauncher!
www.blueskyheart.com (in the desktop pics section). They're just previews of desktop backgrounds but they're just the right size for slauncher!
Here's one i made earlier!