By Cube-like I mean this:

I tried for example Yod'me 3D first which was very nice because it was light and you did not have to install it. There are others that were not as fast a Yod'me.
But then I tried Xdesk which was for me excellent. I has many mouse functions to switch between desktops and other features. It is really really simple, and personally I like to keep it that way. It is not as fun as Yod'me though, because with the latter you can see the graphical switch between desktops.
Xdesk page (FREEWARE !) http://www.xdesksoftware.com/ this uses less CPU and RAM than Yod'me, keep that in mind.