
Go to System > Administration > Software Sources, on the Third-Party Software tab click "Add" and add these repositories:
deb http://ppa.launchpad.net/kubuntu-experimental/ppa/ubuntu jaunty main
deb-src http://ppa.launchpad.net/kubuntu-experimental/ppa/ubuntu jaunty main
And update your sources:sudo apt-get update
Then, to only update Amarok (since this is an experimental repository and it's not recommended using it), go to System > Administration > Synaptic Package Manager and search for "Amarok", right click and select "Mark for upgrade", apply changes and after Amarok is upgraded, I suggest removing the 2 repositories I wrote above in this post.That's it, now your Amarok 2 will submit your listened songs to last.fm