Depending on your setup you might find that the default fonts used by the X Window System are too big. Generally, the default setup is good for 1024x768 resolution but on laptops and older hardware that only support 800x600, for example, it is best to use smaller fonts. To achieve this simply edit your /etc/X11/XF86Config file so taht the 75dpi (dots per inch) fonts come before the 100dpi fonts. A snippet from a typical installation is:
Section "Files" RgbPath "/usr/X11R6/lib/X11/rgb" FontPath "/usr/X11R6/lib/X11/fonts/local/" FontPath "/usr/X11R6/lib/X11/fonts/misc/" FontPath "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled" FontPath "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled" FontPath "/usr/X11R6/lib/X11/fonts/Type1/" FontPath "/usr/X11R6/lib/X11/fonts/Speedo/" FontPath "/usr/lib/ghostscript/fonts/" FontPath "/usr/X11R6/lib/X11/fonts/75dpi/" FontPath "/usr/X11R6/lib/X11/fonts/100dpi/" FontPath "/usr/X11R6/lib/X11/fonts/freefont/" FontPath "/usr/X11R6/lib/X11/fonts/sharefont/" EndSection