I have updated the howto to reflect Cyborg_572's wonderful help in resolving the problem of not being able to bind keyboard keys to your wiimote while using REL_X and REL_Y accelerometer input.
For those who followed my howto before 24th June 2008 and have this problem, this can be easily resolved:
Get rid of mouseemu, this is the cause of the problem:
When prompted respond with y to remove the mouseemu package (there may be another library that mouseemu used, just press y and it might remove this extra library too).
sudo aptitude remove mouseemu
Alternatively you can just go into Synaptic package manager and remove the mouseemu package that way.
Unless you want to run sudo modprobe uinput every time you start Ubuntu, it's recommend you make it automatically run upon Ubuntu start up.
Insert this line before exit 0:
gksudo gedit /etc/rc.local
So the whole file should look exactly like this:
You may restart your computer for the settings to take effect, or if you're impatient and want to play with your Wii remote now (without having to restart your computer) you can run this:
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
# In order to enable or disable this script just change the execution
# By default this script does nothing.
sudo modprobe uinput
Now you should have full functionality of you wiimote no matter what tracking mode it's in.