Shapes Builder Tool!

This makes it EASY to create more complex forms out of piled up simple shapes!!!

Here's a link to a video demo! @ http://www.adobe.com/products/illustrator/features._sl_id-contentfilter_sl_types+of+work_sl_for+design.html#content-dotcom-en-feature-illustrator-shape-builder-tool4

Here's the tool's icon

To use the tool, simply click and drag over the selected shapes you want combined, the computer does the work for you.

Here's the starting shapes- notice that I selected  them!

Here I've clicked and dragged with the shapes builder tool across two shapes..... You can alaso try holding the OPTION key to make it "erase" overlapping shapes.

Then the resulting combination of the shapes!!! Super Easy!

Try it out!