echo deb http://packages.medibuntu.org/ karmic free non-free | sudo tee -a /etc/apt/sources.list
wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | sudo apt-key add - && sudo apt-get update

for dvd 

sudo apt-get install libdvdcss2

for MP3, flash, etc.. 

sudo apt-get install ubuntu-restricted-extras

for skype 

sudo apt-get install skype