I recently bought a Graphire4 to use as an alternative to a mouse at work, but I set it up on my Linux laptop for about a week first. It took about an hour of Googling and tweaking to get it working, but it works perfectly under Linux. I only tried it in the Gimp, but I really enjoyed it. I'm a pencil artist, and I was able to very quickly start creating sketches that were equivalent to what I could do with a real pencil and paper.
I was using it on Kubuntu 6.06, which already had the kernel configured for it. I had to install the wacom-tools package also. You may need to look under /dev/input to verify that the wacom device is a pointer to eventXX. It appeared that the tablet would use a different eventXX (where XX is a number) between reboots, but the link always tracked correctly. I think that happens due to a udev rule, but I didn't have to do anything to set that up.
Good luck and have fun with it! I've since taken mine to work, where the pressure sensitivity is mostly going to waste. But it is a very comfortable mouse alternative, and I've found I'm a lot faster with spreadsheets and other tasks with a tablet over a mouse. I'm now considering an Intuos for artwork at home.
You can get lots of info here:
http://linuxwacom.sourceforge.net/index.php/main
Here's the applicable parts of xorg.conf:
Code:
Section "InputDevice"
Driver "wacom"
Identifier "stylus"
Option "Device" "/dev/input/wacom"
Option "Type" "stylus"
EndSection
Section "InputDevice"
Driver "wacom"
Identifier "eraser"
Option "Device" "/dev/input/wacom"
Option "Type" "eraser"
EndSection
Section "InputDevice"
Driver "wacom"
Identifier "cursor"
Option "Device" "/dev/input/wacom"
Option "Type" "cursor"
EndSection
Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0"
InputDevice "Generic Keyboard"
InputDevice "USB Mouse"
InputDevice "stylus" "SendCoreEvents"
InputDevice "cursor" "SendCoreEvents"
InputDevice "eraser" "SendCoreEvents"
EndSection