Not a howto: more like a quick tip. To make your screen size larger than the physical size of your monitor, you can add the following to your /etc/X11/xorg.conf file:
Viewport 0 0
# the following line will create a virtual screen size of 800 px wide x 1800 px high
Virtual 800 1800
This will allow you to remove the top and bottom borders from applications such as Konqueror, by scrolling the virtual screen with the mouse. You will then be able to fill the whole of your visable screen with the applications content.
See the attached png for an example.