I guess you're supposed to ctrl+alt+mousegrab your desktop, then drag the cube around. 3d effects and such are configured from within the compizfusion control panel, which you need to have installed -- if you can't find the settings there, you might not find them anywhere (simple

).
By the way, it's all explained in the CF control panel - keys to enable/"use" the effects and all, so maybe you should read it more carefully next time.