I have to compile the source of wdaemon for my wacom tablet. You may need to read my old blog post, Use wdaemon for hotplugging, for more detail, I only write essential stuff here, so please also read it. I like to put source under ~/var/src. 

mkdir -p ~/var/src
cd ~/var/src
sudo apt-get install subversion libc6-dev
svn co https://jake.ruivo.org/wdaemon/trunk/ wdaemon
cd wdaemon
make
sudo make install
Adjust the main program 

sudo ln -s /usr/local/bin/wdaemon /usr/bin/
In my old post, I did 

cp /usr/local/etc/rc.d/init.d/wdaemon /etc/init.d/
However, that initiation boot script doesn't work on Ubuntu without modification. So I just add necessary command to /etc/rc.local 

modprobe uinput
/usr/bin/wdaemon -c /etc/wdaemon.conf -f
Set up udev 

sudo cp udev/*.rules /etc/udev/rules.d
sudo mkdir /etc/udev/scripts
sudo cp udev/is_uinput.sh /etc/udev/scripts
I still need to modify the `60-wacom.rules` 

# udev rules for wacom devices
# will create:
#       /dev/input/wacomX
#       /dev/input/wacom-tablets/model-tabletX
#       /dev/input/wacom-tablets/model-unique PCI/USB path
#
KERNEL=="event*", SYSFS{idVendor}=="056a", SYMLINK+="input/wacom"
KERNEL=="event*", SYSFS{idVendor}=="056a", SYSFS{idProduct}=="00b5", SYMLINK+="input/wacom-tablets/intuos3-6x11 input/wacom-tablets/intuos3-6x11-%b"
Note that this is for my wacom tablet. You can try to re-plug and see if there is a new device come up in /dev/input/wacom-tablets. If there is, then you don't need to modify as I did; if not, try to modify. After re-plugging your tablet, run 

sudo sh -c "wdaemon -a > /etc/wdaemon.conf"
This will automatically create the configuration for wdaemon. Now, you can run 

modprobe uinput
/usr/bin/wdaemon -c /etc/wdaemon.conf -f
If /dev/input/ has new device, then it's time to modify your xorg.conf. If you already added those InputDevice for you wacom tablet, then you only need to change the device path. Here is mine 

Section "ServerLayout"
 ...
 InputDevice     "stylus"    "SendCoreEvents"
 InputDevice     "cursor"    "SendCoreEvents"
 InputDevice     "eraser"    "SendCoreEvents"
 InputDevice      "pad"
 ...
EndSection

Section "InputDevice"
 Driver      "wacom"
 Identifier  "stylus"
 Option      "Device" "/dev/input/uinput-devices/uinput-wacom-intuos3-6x11-tablet"
 Option      "Type"      "stylus"
#   Option      "ForceDevice"   "ISDV4"     # Tablet PC ONLY
 Option      "USB"       "on"
EndSection

Section "InputDevice"
 Driver      "wacom"
 Identifier  "eraser"
 Option      "Device" "/dev/input/uinput-devices/uinput-wacom-intuos3-6x11-tablet"
 Option      "Type"      "eraser"
#   Option      "ForceDevice"   "ISDV4"     # Tablet PC ONLY
 Option      "USB"       "on"
EndSection

Section "InputDevice"
 Driver      "wacom"
 Identifier  "cursor"
 Option      "Device" "/dev/input/uinput-devices/uinput-wacom-intuos3-6x11-tablet"
 Option      "Type"      "cursor"
#   Option      "ForceDevice"   "ISDV4"     # Tablet PC ONLY
 Option      "USB"       "on"
EndSection

Section "InputDevice"
 Driver      "wacom"
 Identifier  "pad"
 Option      "Device" "/dev/input/uinput-devices/uinput-wacom-intuos3-6x11-tablet"
 Option      "Type"      "pad"
 Option      "USB"       "on"
EndSection
Press ctrl+alt+backspace to restart your X, log in, try you tablet with re-plugging it.