A friend recommended Fence not that long ago so I have now used it for a while and I like it a lot!
With Fence it is very easy to organize your computer desktop and arrange things in to modern looking windows.

And if you give a presentation or if you for other reasons want to hide all items on the desktop you can just double click anywhere on the desktop which will then hide all the objects:

Double click again to show them.

Also, creating a new window is easy, just drag a rectangle whilst holding in right mouse button, give it a name and hit ok. That’s it!

There is a free version and a pay version which you both can download from here: http://www.stardock.com/products/fences/

It is supported on: Windows XP, Windows Vista, and Windows 7 and hardly use any system resources!