VirtualBox 3.2 was released a couple of days back, as Oracle VirtualBox 3.2, with some exciting new features. It has not yet come to the official Ubuntu repository, but you can install it from the VirtualBox Repository. Here is how to do it:

• Open the Terminal/Konsole. (In GNOME Applications -> Accessories -> Terminal. In KDE, bring up the KRunner with ALT+F2 and type “konsole“.)
• Open /etc/apt/sources.list for editing with the command:

sudo gedit /etc/apt/sources.list

Note: If you are in KDE, replace gedit with kate in the command above.

• In the file source.list, add one of the following, whichever is appropriate:

For Lucid (10.04):

deb http://download.virtualbox.org/virtualbox/debian lucid non-free

For Karmic (9.10):

deb http://download.virtualbox.org/virtualbox/debian karmic non-free

Save and exit.

• Install the GPG key with the command:

wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add -

• Now update the software source and install VirtualBox 3.2 with the commands:

sudo apt-get update && sudo apt-get install virtualbox-3.2

• Finally install dkms with:

sudo apt-get install dkms