1.Install compizconfig-settings-manager in Synaptic.
2.Then, run this in System->Preferences->CompizConfig-Settings-Manager.
To enable the cube, check Desktop Cube, Rotate Cube, Cube Reflection and Deformation, then you could use it by holding ctrl-alt left-mouse button.
To customize, or change the top and bottom photos of the cube or cube caps, click Cube Reflection and Deformation->Cube caps->Appearance. Click New in top image files and bottom image files and choose your own picture. That's it!