Dark Plastik is a nice little black theme I made, based on my DarkPlastik colour scheme.
Has a debian wallpaper, but for those not running debian, wallpaper is easy to change
1) Download the file
2) Go into kcontrol (control center), to Appearance & Themes --> Themes.
3) Click "Install new theme", select the downloaded file
4) Select 'Dark Plastik' in the list
Make sure you restart KDE after you install this theme! If you don't, then the colour screw up until you next start KDE.
Hope you guys like it!