Multimedia capabilities

• Select System -> Adept Manager
• Search for restricted
• Depending on your Ubuntu branch (Ubuntu/Kubuntu/Xubuntu), select [branch]-restricted-extras and mark it to install. For Kubuntu by example - it would be kubuntu-restricted-extras.

compiz - or 3D Effects
If you want to enable the 3D Effects in Kubuntu - you'll need to install the following packages.

sudo aptitude install compiz compiz-kde emerald compizconfig-settings-manager fusion-icon

compizconfig-settings-manager will install loads of Gnome libraries - but that should not be the matter with nowadays harddisk sizes.
After installation is complete - go to Start -> System -> Compiz Fusion Icon and start it. Go with the right mouse button on it and start compiz.

Skype

• Select Synaptic ->Repositories -> Third Party Software -> + ADD
• Paste this into the APT Line: deb http://download.skype.com/linux/repos/debian/ stable non-free
• Then search for Skype, check the corresponding box and then click Install

Google Earth / Desktop

• Download PGP Key : linux_signing_key.pub
• Select Synaptic -> Repositories -> Authentication -> + IMPORT KEY FILE
• Browse to the directory where you downloaded linux_signing_key.pub and select that
• Select Synaptic -> Repositories -> Third Party Software -> + ADD
• Paste into the APT Line: deb http://dl.google.com/linux/deb/ stable non-free
• Click Reload
• Then search for Google and install the Google applications of your choice

VMware Server (Run Windows and Windows applications in Ubuntu 7.10)

• Register for a VMware Server serial number here.
• from terminal sudo apt-get install build-essential
• download VMware Server for Linux - Binary (.tar.gz) here.
• from terminal cd dir to the downloaded file and type tar zvxf VMware-server-1.0.4-56528.tar.gz
• from terminal cd vmware-server-distrib/
• from terminal sudo ./vmware-install.pl
• hit the enter key for every question asked, if question doesn't accept the Enter key then select Yes.
• Run VMware Server by selecting Applicatoins -> System Tools -> VMware Server Console

Virtual Box
Add one of the following lines according to your distribution to your /etc/apt/sources.list:

deb http://www.virtualbox.org/debian gutsy non-free
deb http://www.virtualbox.org/debian feisty non-free
deb http://www.virtualbox.org/debian edgy non-free
deb http://www.virtualbox.org/debian dapper non-free

The innotek public key for apt-secure can be downloaded here. You can add this key with

apt-key add innotek.asc

The key fingerprint is

6947 BD50 026A E8C8 9AC4  09FD 390E C3FF 927C CC73
innotek GmbH (archive signing key) 

You will need to install some additional libraries on your Linux system in order to run VirtualBox - in particular, you will need libxalan-c, libxerces-c and version 5 of libstdc++. How to install these will depend on the Linux distribution you are using. On gutsy a

sudo aptitude install virtualbox

is enough.
Check the homepage of the virtualbox project for more details.

Multimedia stuff
as the VLC player - check out VLC media player for Ubuntu Linux homepage.