How to reduce the size of all gnome-shell icons?

Is it me or is the size of icons in Gnome 3.2 huge? It makes my 1200*800 resolution look like a netbook interface. Please how do I reduce icons size?

To configure the layout of the application icons in the GNOME Shell, you have to modify /usr/share/gnome-shell/theme/gnome-shell.css. Note that the contents of this file may vary as it is dependent on the particular theme that you are using. In the case of the Dark Glass theme, here are the modifications necessary to reduce the size and layout of the displayed icons by 50% in Applications Overview.

.icon-grid {
    spacing: 18px;                       /* was 36px */
    -shell-grid-item-size: 35px;         /* was 70px */
}

.all-app .icon-grid {
    -shell-grid-item-size: 59px;         /* was 118px */
}

.all-app .overview-icon {
    icon-size: 48px;                     /* was 96px */
}

Read more here.

For size only: Open nautilus, go to Desktop folder, click in the upper right corner on the icon with the four squares, again the four squares and then set the size using the provided slider.