Playing DVD's (Ubuntu 8.10)

Add the repositories first:

sudo wget http://www.medibuntu.org/sources.list.d/intrepid.list --output-document=/etc/apt/sources.list.d/medibuntu.list

Then add the GPG key:

sudo apt-get update && sudo apt-get install medibuntu-keyring && sudo apt-get update

Then install libdvdcss2:

sudo apt-get install libdvdcss2