"Step 1
"Install gtk-qt-engine package.
"Fedora: sudo yum install gtk-qt-engine
"Direct download of the package(fedora rpm) can be found here
"Ubuntu 8.04: sudo apt-get install gtk-qt-engine-kde4
"Ubuntu 8.10: sudo apt-get install gtk-qt-engine
"Now go to System Settings > Appearance > Click on the Gtk Styles and Fonts tab on the left side and select the following options there:"