One more tool to modify the objects after they are placed on canvas. Now you can rotate them. Click on this icon in the toolbar and then click on the object (group of cubes) that you want to rotate.
The object will rotate around the axis that your view is most aligned with passing through the cube that is approximately at the center of the structure.
Here is an example.
With move and rotate you can modify your 3D sketch more flexibly now.
And here is a sketch I made this week. Enjoy!
http://www.3dtin.com/_widget/?uid=qo&w=500&h=412