The default font and toolbar sizes for GTK-base applications (Pidgin, for example) do not lend themselves to the small screen-size of the EEE PC. Using these settings, you can customize these sizes to suit your tastes.

1. Open a terminal

2. Open your GTK preferences file for editing, telling :

kwrite /home/user/.gtkrc-2.0 

3. Paste the following code into your kwrite window:

gtk-icon-sizes = "gtk-menu=8,8:
                  gtk-button=8,8:
                  gtk-small-toolbar=8,8:
                  gtk-large-toolbar=12,12:
                  gtk-dialog=16,16:
                  gtk-dnd=16,16"
gtk-toolbar-style = GTK_TOOLBAR_ICONS
gtk-font-name = "DejaVu Sans 8"

I chose DejaVu Sans 8 because I though it looked nice, but you can use whatever font you wish. To get a list of the fonts installed on your system, use the command:

fc-list

You can apply the same preferences for GTK applications running as root (Synaptic Package Manager, Network Connections) by having the GTK preference file copied to /root:

sudo cp .gtkrc-2.0 /root/.gtkrc-2.0

A more in-depth explanation of how to check the fonts installed on your system can be found on the KDE TechBase