Desktop themes are nowadays very popular. They change the way your desktop looks in general.
New Wallpaper, Icons for [my computer], [recyclebin], and [computer network], the sounds change, the colors of your buttons/systems tray, and sometimes even you mouse pointers change with the theme you load!
Are You also tired of those blue windows clouds, or the green windows default screen. Download these themes and You will have something else to look at!
an example: