Removing Ubuntu One

As it says in the title. I want to get rid of this useless application ubuntu one. I've removed the application files from the software centre, but the icon is still shown.

Open a terminal CTRL+ALT+T and type:

killall ubuntuone-login ubuntuone-preferences ubuntuone-syncdaemon

sudo rm -rf ~/.local/share/ubuntuone

rm -rf ~/.cache/ubuntuone

rm -rf ~/.config/ubuntuone

mv ~/Ubuntu\ One/ ~/UbuntuOne_old/``

(source: Ubuntu One) - Support pages no longer exist.

And then just to make sure.

sudo apt-get remove --purge ubuntuone-*

(Note for Ubuntu 14.*: Please refer to iheggie's answer to avoid the removal of the Ubuntu Desktop.)

Edit: The reason for this method over more simple methods is to ensure that the configurations, cache and any other preferences do not remain on your system; if we've learnt anything from Windows it's that prefetch is more than enough to slow a system down, it's good practise to clear your system now then to forget what needs to be cleaned later.

Of course, you can remove Ubuntu One (U1) either via the Software Centre (as mentioned in other answer) or through the terminal using:

sudo apt-get purge ubuntuone-*

This will remove the U1 application along with the various U1 plugins for things like rhythmbox, etc.

Under ubuntu trusty 14.04, I used @cossacksman's answer, except I removed the packages one by one using synaptic. I had to leave ubuntuone-client-data installed as both apt and synaptic wanted to remove ubuntu-desktop as well.