1. Install the Linux Wacom drivers. On Arch Linux, you can find it on AUR.
2. Configure the X.Org server to use it. I post my xorg.conf file as an example:


Section "ServerLayout"
Identifier "X.org Configured"
Screen "Screen0"
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "stylus" "SendCoreEvents"
InputDevice "eraser" "SendCoreEvents"
InputDevice "touch" "SendCoreEvents" # Only a few TabletPCs support this typeEndSection

EndSection

Section “Files”
ModulePath “/usr/lib/xorg/modules”
FontPath “/usr/share/fonts/misc”
FontPath “/usr/share/fonts/100dpi:unscaled”
FontPath “/usr/share/fonts/75dpi:unscaled”
FontPath “/usr/share/fonts/TTF”
FontPath “/usr/share/fonts/Type1″
EndSection

Section “Module”
Load “dri”
Load “xtrap”
Load “dbe”
Load “glx”
Load “extmod”
Load “freetype”
EndSection

Section “InputDevice”
Identifier “Keyboard0″
Driver “kbd”
Option “XkbLayout” “es”
EndSection

Section “InputDevice”
Identifier “Mouse0″
Driver “mouse”
Option “Protocol” “auto”
Option “Device” “/dev/input/mice”
Option “ZAxisMapping” “4 5 6 7″
EndSection

Section “InputDevice”
Driver “wacom”
Identifier “stylus”
Option “Device” “/dev/ttyS0″ # SERIAL ONLY
Option “Type” “stylus”
Option “ForceDevice” “ISDV4″ # Tablet PC ONLY
EndSection

Section “InputDevice”
Driver “wacom”
Identifier “eraser”
Option “Device” “/dev/ttyS0″ # SERIAL ONLY
Option “Type” “eraser”
Option “ForceDevice” “ISDV4″ # Tablet PC ONLY
EndSection

Section “InputDevice”
Driver “wacom”
Identifier “cursor”
Option “Device” “/dev/ttyS0″ # SERIAL ONLY
Option “Type” “cursor”
Option “ForceDevice” “ISDV4″ # Tablet PC ONLY
EndSection

Section “InputDevice”
Driver “wacom”
Identifier “pad”
Option “Device” “/dev/ttyS0″ # SERIAL ONLY
Option “Type” “pad”
EndSection

# Uncomment the following section if you you have a TabletPC that upports touch
Section “InputDevice”
Driver “wacom”
Identifier “touch”
Option “Device” “/dev/ttyS0″ # SERIAL ONLY
Option “Type” “touch”
Option “ForceDevice” “ISDV4″ # Serial Tablet PC ONLY
# Adding manual calibration, since proper calibration seems impossible.
Option “BottomX” “915”
Option “BottomY” “940”
Option “TopX” “48”
Option “TopY” “90”
EndSection

Section “Monitor”
#DisplaySize 260 160 # mm
Identifier “Monitor0″
VendorName “LEN”
ModelName “4011”
Option “DPMS”
EndSection

Section “Monitor”
Identifier “HDMI-1″
Option “Ignore” “True”
EndSection

Section “Monitor”
Identifier “HDMI-2″
Option “Ignore” “True”
EndSection

Section “Device”
Identifier “Card0″
Driver “intel”
VendorName “Intel Corporation”
BoardName “Mobile 4 Series Chipset Integrated Graphics Controller”
BusID “PCI:0:2:0″
Option “monitor-HDMI-1″ “HDMI-1″
Option “monitor-HDMI-2″ “HDMI-2″
EndSection

Section “Screen”
Identifier “Screen0″
Device “Card0″
Monitor “Monitor0″
DefaultDepth 24
Option “RandRRotation” “on”
SubSection “Display”
Modes “1280×800″ “1024×768″ “800×600″ “640×480″
EndSubSection
EndSection

Section “Extensions”
Option “Composite” “Enabled”
EndSection

And thats’s all! With just these two steps you can use your pen or your finger to control the screen :)