Medibuntu (Multimedia, Entertainment & Distractions In Ubuntu) is a repository of packages that cannot be included into the Ubuntu distribution for legal reasons (copyright, license, patent, etc).
The Medibuntu repository is available (was released seconds ago) for Ubuntu 10.10 Maverick Meerkat - I know many of you were waiting for it so here is how to add it to your sources.list:
sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list cd && wget http://packages.medibuntu.org/pool/free/m/medibuntu-keyring/medibuntu-keyring_2008.04.20_all.deb && sudo dpkg -i medibuntu-keyring_2008.04.20_all.deb && rm medibuntu-keyring_2008.04.20_all.deb sudo apt-get update
To make the Medibuntu packages show up in the Ubuntu Software Center, install this package:
sudo apt-get install app-install-data-medibuntu
You can then install whatever you need from the Medibuntu repositories, like encrypted DVDs support (libdvdcss2), codecs (w32codes or w64codecs) and so on. Please note that some packages are missing such as Google Earth, mplayer-gui and mplayer-nogui as well as Real Player. These packages might just be delayed - you can however try to download the Lucid .debs and install them.
A complete list of packages for the Ubuntu 10.10 Maverick Meerkat Medibuntu repository can be found here.