Ubuntu Geek shows you how to running Ubuntu 11.04 (Natty) unity 3D on Virtualbox 4

Unity provides a complete, simple, touch-ready environment that integrations your applications and your workflow.Unity is designed for netbooks and related touch-based devices. It includes a new panel and application launcher that makes it fast and easy to access preferred applications, such as the browser, while removing screen elements that are rarely used in mobile and netbook computing.

Unity has a vertical task management panel on the left-hand side and a menu panel at the top of the screen. Using a sidebar for task management conserves vertical screen space, which is much more valuable on a widescreen netbook. The task panel displays icons for commonly-used applications and programs that are currently running. Clicking on an icon will give the target application focus if it is already running or launch it if it is not already running. If you click the icon of an application that already has focus, Unity will activate an Expose-style view of all the open windows associated with that application.

  Running Ubuntu 11.04 (Natty) unity 3D on Virtualbox 4