You can join or unite objects using the Join Objects command. Join Objects creates one object from two or more objects. The Join Objects command is used with overlapping objects.

Use several overlapping ellipses to create a cloud. Using the Join Objects command creates one object by merging the areas that do not overlap with the areas that do.

Here is a step by step on how to make a scalloped border using the join command:

Draw a solid colored circle about 1" at the top of your page.

Ctrl-Drag to duplicate the circle and place it at the bottom of the page.

Select all (ctrl-A) and go to Draw -> Align Objects -> Center.

Go to Tools -> Blend.  Step value: 8

Click on the new circles that were created from the blend command, then right click and ungroup.

Select all (ctrl-A) and then hit the plus sign (+) to join the objects.  Draw a line from the top of the page to the bottom (hold the shift key to keep the line straight)

Select all (ctrl-A) and go to Draw -> Align Objects -> Center.

With both objects selected, hit the minus sign (-) to slice the object.  Click and drag the two halves apart and you now have a left and right scalloped border.