XDESK is a program that allows you to open an application on your desktop and with a keystroke or two you can switch to another empty desktop without closing down the application. You can return to the original desktop and the applications running on it whenever convenient. The result is something as good as having multiple monitors but in less space, at a much lower price and with a lot of smart features to manage that extra space. And of course that XDESK will do much more than that!
Here are some of the pages where you can find more details:
XDESK Screenshots
XDESK tips and tricks
More about Virtual Desktop Managers
How XDESK is rated (you can click on pictures or links to view the reviews):