VirtualBox 4.1.2 is Released

Install VirtualBox 4.1.2 on Ubuntu Natty-Oneiric/Linux Mint
Oracle has released VirtualBox 4.1.2, a maintenance release of VirtualBox 4.1 which includes fixes and GUI support for Linked Clones.

VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2.

To install VirtualBox Open Terminal (Press Alt+F2 and type: gnome-terminal -or- Press Ctrl+Alt+T) and copy the following commands in the terminal:

Terminal Commands:
echo deb http://download.virtualbox.org/virtualbox/debian $(lsb_release -sc) contrib | sudo tee /etc/apt/sources.list.d/virtualbox.list
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update && sudo apt-get install virtualbox-4.1

When installation finished, Start VirtualBox (Press Alt+F2 and type: virtualbox) and use.

If you want to install additional features like USB 2.0 support, You need to install VirtualBox Extension Pack which you can download from here.
If you want to install guest additions on Ubuntu 11.04/Ubuntu 11.10/Linux Mint copy the following command in the terminal:

Terminal Command:
sudo apt-get install virtualbox-ose-guest-utils

That's it
Here is the Homepage of VirtualBox.