Source: http://arstechnica.com

Fixing the fonts

By default, the Eee uses size 10 fonts in most of the programs.
I got frustrated with that font size, because it makes user interface
text take up way too much space. Unfortunately, there is no central
location where you can go to change all the font sizes. You have to
configure the font sizes individually for Firefox, GTK, and KDE. To
change the default KDE font size, launch the kcontrol utility from the